Vox Meditantis

Dr Mary Julia Wade (1928-2005) spent half a century mapping life across geological time – from the planet’s earliest complex organisms to Queensland’s Cretaceous dinosaurs. Her 1968 paper on how soft-bodied Ediacaran animals preserved in sandstone established the taphonomic framework that still guides interpretation of Earth’s first animal communities, yet her name remains largely absent from popular accounts of these 550-million-year-old fossils. Working first at the University of Adelaide alongside Professor Martin Glaessner, then as Curator and Deputy Director at Queensland Museum, Wade described new Precambrian genera with triradial symmetry, supervised the excavation of over 3,000 dinosaur footprints at Lark Quarry, and built networks across western Queensland that enabled major vertebrate discoveries.

Wade’s career illuminates how explanatory labour – the intellectual work of figuring out how fossils preserve – becomes invisible infrastructure once established, and how women’s contributions disappear into collaborative credits or institutional hierarchies. Her story raises questions about scientific memory: why do we remember the fossils and evolutionary theories, but not the woman who solved the preservation puzzle that made studying them possible?

Welcome, Dr Wade. It’s 2025, twenty years since you passed away. I’m grateful for this chance to speak with you, particularly because your work underpins so much contemporary research on the Ediacara Biota, yet your name rarely appears in public discussions of these fossils.

Thank you for having me. Twenty years on, is it? That’s a peculiar thought. I suppose I shouldn’t be surprised about the name business – it was always going to be “Glaessner’s Ediacaran work” or “Sprigg’s discovery.” That’s how these things settle into the record.

Let’s start at the beginning. You grew up in rural South Australia, then on Thistle Island. What drew you to geology?

Thistle Island, yes – we moved there when I was seven. My father had various positions, country life mostly. The island was extraordinary for a child interested in the natural world. Rocks everywhere, of course, but more than that – you could see the bones of the landscape, if you like. Strata exposed in the cliffs, fossils weathering out of limestone. I spent hours just looking, collecting bits and pieces.

When I went to Adelaide for university – I’d been sent away to Wilderness School on scholarship at thirteen, which was hard but necessary – I initially thought I might study chemistry. Professor Henry Caselli Richards taught geology, though, and once I’d taken it as an elective, that was that. Field work suited me. I liked being outdoors, I liked the puzzle-solving aspect, and frankly, it seemed more “appropriate” for a woman than some other sciences. Less time in laboratories with male colleagues, more time on your own with rocks and notebooks.

You completed your Honours in 1954 in micropalaeontology, then your PhD in 1959 under Martin Glaessner’s supervision, working on Tertiary foraminifera. But you stayed on at Adelaide as a Senior Demonstrator for twelve years. Can you talk about that period?

That was… well, it was difficult. I’d finished the PhD, I was publishing, I was doing good work. But there was simply no prospect of a permanent academic position. Demonstrator meant teaching – showing students how to identify fossils under microscopes, running practical sessions, preparing specimens. Essential work, mind you, but not research-focused, and certainly not a path to a professorship.

This was the late 1950s, early 1960s. Dorothy Hill at Queensland was an absolute exception – first woman professor at an Australian university, first woman Fellow of the Academy of Science. She was extraordinary, and everyone knew it. For the rest of us, the ceiling was demonstrator or maybe senior demonstrator if you were lucky. You did your research in the margins, evenings and weekends, because the institution wasn’t structured to support you as a researcher.

Martin needed someone to work on the Ediacaran material Reg Sprigg had found. I had the micropalaeontology training, I understood preservation, I was there and available. So I took it on.

Your 1968 paper in Lethaia – “Preservation of soft-bodied animals in Precambrian sandstones at Ediacara, South Australia” – has been described as setting the stage for all subsequent work on Ediacaran taphonomy. Walk me through what you discovered.

Right. So Sprigg had found these extraordinary fossils in the Flinders Ranges in 1946 – disc-shaped impressions, frond-like forms, things that looked vaguely like jellyfish. Martin recognised they were Precambrian, which made them the oldest animal fossils known at the time. That was the headline: complex life before the Cambrian.

But how they preserved was the puzzle. These were soft-bodied organisms – no shells, no hard parts. Normally they’d decay within days or weeks and leave nothing. Yet here they were, preserved in sandstone as moulds and casts, some in extraordinary detail. You could see the structure of their bodies, the patterns on their surfaces.

I spent months in the Flinders Ranges, examining the specimens in situ, looking at the sedimentology, the bedding planes. What I noticed was that the fossils naturally grouped into two categories based on their preservation. I called them “resistant” and “non-resistant.”

Can you define those terms technically?

Certainly. Non-resistant organisms – mostly the medusoid forms, the disc-shaped ones – collapsed or decayed before the sediment had fully lithified. You find them in convex relief on the bases of sandstone beds. The organism was smothered by sediment, it decomposed relatively quickly, and the space it occupied became a mould. Later, that mould might fill with sand from below, creating a counterpart cast.

Resistant organisms – the more rigid forms, possibly with some internal structure or tougher organic material – supported the weight of the covering sediment until it had set. They’re preserved in negative relief on bed bases. The body didn’t collapse immediately, so the sediment moulded around it before decay proceeded.

That distinction seems straightforward now, but it wasn’t obvious at the time?

Not at all. People were arguing about whether these were even animals. Some thought they were sedimentary structures, gas bubbles, algal growths. Understanding the preservation was crucial to understanding what the fossils actually were.

You attributed the formation of counterpart casts to upward movement of sediment from underlying beds – what’s now sometimes called the “waterbed hypothesis.” Explain that mechanism.

The waterbed hypothesis – that’s not what I called it in 1968, but it’s apt. Think of a waterbed mattress: a flexible but inextensible membrane holding incompressible fluid, with lateral pressure keeping everything in place.

At Ediacara, you had a microbial mat – that sticky, cohesive layer of bacteria and other microorganisms – covering the seafloor. The mat was the “mattress.” Below it, you had water-saturated sediment, essentially incompressible pore fluid. The mat was laterally continuous, held in place by its own cohesion and perhaps by slight cementation.

When a storm deposited sand rapidly on top, organisms were smothered and eventually decayed, leaving voids. But because the sediment below the mat was still water-saturated and laterally constrained, pressure from above could force sediment upward through weak spots in the mat – particularly where organisms had been – creating casts that replicated the shape of the now-decayed body.

This explains why you get both moulds (on the base of the overlying bed) and counterpart casts (on the top of the underlying bed). It’s a pressure-driven movement of unconsolidated sediment through the mat.

Jim Gehling later proposed the “death mask” hypothesis – early pyrite precipitation on organism surfaces. How does that differ from your interpretation?

Jim’s death mask model focuses on early diagenetic mineralisation. The idea is that as organisms decayed, sulphate-reducing bacteria produced hydrogen sulphide, which reacted with iron in the sediment to precipitate pyrite directly on the organism’s surface. This pyrite “mask” preserved fine morphological detail and helped stabilise the mould before significant decay occurred.

Both mechanisms probably operated. The waterbed model explains the mechanical formation of counterpart casts. The death mask model explains the chemical stabilisation that allowed fine details to preserve. They’re complementary, not contradictory. Recent experimental work by Mary Droser’s group and others has shown that both microbial mats and early silica or pyrite precipitation played roles.

The key insight from my 1968 paper was recognising that preservation mode correlated with organism resistance – that different body plans preserved differently because they had different structural properties. That let you start inferring things about the organisms’ biology from how they fossilised.

You formally described several Ediacaran taxa, including Skinnera brooksi and Hallidaya brueri – small disc-shaped organisms with triradial symmetry from the Northern Territory. What can you tell me about those?

Ah, Mount Skinner. A.L. Halliday and M.M. Bruer – geologist and field assistant for Kennecott Explorations – found fossiliferous deposits there in the 1960s. They contacted me at Adelaide, and I went out with them to collect additional material.

There were two forms. Form A I named Hallidaya brueri after the discoverers. Form B I named Skinnera brooksi after the location. Both were small – typically about a centimetre across – with three-fold symmetry. Three large central depressions, possibly stomach pouches, connected by canals to smaller peripheral depressions around the rim. Quite beautiful little things, really.

The triradial symmetry was fascinating because it’s essentially unknown in modern animals. You get radial symmetry – starfish, jellyfish – and bilateral symmetry, but true triradial organisation doesn’t persist past the Ediacaran. It suggests these organisms represent body plans that were evolutionary experiments, lineages that didn’t continue into the Phanerozoic.

Some researchers now think Skinnera and Hallidaya might be the same organism – upper and lower surfaces of the same body plan. Did you consider that?

I did note they occurred together and had similar size ranges. It’s certainly possible they’re taphomorphs – different preservational expressions of one organism. But the morphological differences seemed significant enough to warrant separate descriptions at the time. Subsequent workers with more specimens and better analytical tools might revise that, and that’s as it should be. Taxonomy is always provisional.

In 1971 you left Adelaide for Queensland Museum. What prompted that move?

No prospect of promotion. Twelve years as a demonstrator, and it was clear I’d stay a demonstrator. The University structure simply didn’t accommodate women advancing to lectureships, let alone senior positions. Dorothy Hill was unique – she’d gone to Cambridge, published extensively, had international recognition before the barriers fully solidified. For women coming through in the 1950s and 1960s, the doors were largely closed.

Queensland Museum advertised a Curator of Geology position. It was a genuine research role, with collection responsibilities and fieldwork opportunities. I applied, and Alan Bartholomai – the Director – offered me the position. In 1980 I became Deputy Director. Twenty-two years at the Museum, and I like to think I did good work there.

You quadrupled the fossil collections during your tenure. What did that entail?

A lot of driving through western Queensland, for starters. The Museum’s collections in 1971 were respectable but limited. Queensland has an extraordinary fossil record – Palaeozoic, Mesozoic, everything – but specimens were scattered across the state or sitting in private collections.

I established networks with station owners, amateur collectors, local enthusiasts. People would ring up: “I found something odd in the creek bed.” I’d drive out, have a look, arrange collecting if it warranted. Built relationships in Winton, Richmond, Hughenden, all through the western districts. Those relationships led to major discoveries – Lark Quarry, the Cretaceous marine reptiles, numerous sauropod specimens.

I also worked on multiple groups simultaneously. Ordovician nautiloids from north-western Queensland – described over 200 specimens from Black Mountain that Mary Wade and colleagues had collected. Dinosaur trackways. Pliosaurs. Cretaceous ichthyosaurs. Molluscs from the Great Artesian Basin deposits. People sometimes thought I spread myself too thin, but each project informed the others. Understanding preservation in one context helps you interpret fossils in another.

Let’s talk about Lark Quarry. In 1976-77, you and Tony Thulborn supervised excavation of over 3,000 dinosaur footprints. Describe that site.

Lark Quarry is in the Tully Ranges, about 110 kilometres southwest of Winton. Glen Seymour, a station manager, found the trackways in the 1960s – thought they were fossilised bird tracks initially. By the time Tony and I got out there in the mid-1970s, it was clear they were dinosaur footprints, and an extraordinary number of them.

The site preserves a moment roughly 95 million years ago, when a group of at least 150 small dinosaurs – coelurosaurs about chicken-sized, and slightly larger ornithopods – were at a lake edge. The tracks show them moving in the same direction, quickly, chaotically. We interpreted it as a stampede, possibly triggered by a large theropod whose tracks also appear at the site.

The excavation was painstaking. You’re exposing a bedding plane, carefully cleaning away overlying sediment without damaging the impressions. Each track had to be mapped, photographed, cast if possible. We worked in shifts, often in brutal heat. But the result – the world’s only known record of a dinosaur stampede – justified the effort.

Some recent researchers have challenged the stampede interpretation, suggesting it might be a natural river crossing. How do you respond?

Science progresses by challenging interpretations. If new evidence suggests a different scenario, that’s good. The tracks are the data; the interpretation is our best hypothesis given available evidence. What matters is that the site is preserved and studied. That’s why we pushed for heritage listing, why it’s now on the National Register. The tracks themselves are the permanent record.

You also recovered Cretaceous marine reptiles – pliosaurs, ichthyosaurs. Tell me about that work.

Queensland’s inland was once covered by a vast shallow sea – the Eromanga Sea. Sediments from that period preserve marine reptiles that were swimming around 100 million years ago. There was a Cretaceous ichthyosaur specimen that had been sitting in Museum storage since 1935. I arranged for its preparation and display – got it properly cleaned, mounted, interpreted.

I also excavated what’s described as the most complete pliosaur fossil presently known. Pliosaurs were massive marine predators, short-necked relatives of plesiosaurs. This specimen was from near Hughenden. Again, it was network-building that made it possible – someone on a station knew where to look, rang me, I went out with a team.

And I recovered the site for Rhoetosaurus, Australia’s only Jurassic sauropod, which had been lost since the 1920s. Relocating historical sites, securing new specimens – that was ongoing collection-building work.

You also recovered a second Muttaburrasaurus skull in 1987. That’s Queensland’s iconic dinosaur.

Yes, the Dunluce skull. John Stewart-Moore and young Robert Walker found it on Dunluce Station between Hughenden and Richmond. It’s from the Allaru Mudstone, slightly older than the original Muttaburrasaurus langdoni holotype. Ralph Molnar thought it might represent a separate species – Muttaburrasaurus sp. – but more material would be needed to confirm that.

Muttaburrasaurus has become Queensland’s fossil emblem, which is lovely. It’s one of Australia’s most complete dinosaurs. Seeing those fossils spark interest in children who visit museums or Lark Quarry – that’s the real payoff. Not everyone will become a palaeontologist, but if they leave with a sense of deep time, of Queensland’s ancient past, that’s valuable.

Looking back at your Ediacaran work, what do you think was most significant about your 1968 preservation paper?

That it provided a mechanism. Before that, there were fossils and speculation. I showed how soft tissues could preserve in sandstone under specific conditions – microbial mat substrates, rapid burial, differential resistance to decay, sediment mobility creating casts. That framework let other researchers interpret new finds, compare preservation modes across sites, infer ecological and taphonomic conditions.

The irony is that explanatory frameworks become invisible once they succeed. No one now thinks, “I must reference Wade 1968 to understand why this is a mould and that’s a cast.” It’s simply how you think about Ediacaran preservation. The knowledge has been absorbed into the field’s infrastructure.

Your name is often attached to Martin Glaessner’s in citations – “Glaessner and Wade.” How do you feel about that collaborative framing?

Martin was my supervisor, an established professor, internationally recognised. When we published together, his name carried weight. That’s just how academic hierarchies work. I don’t think Martin deliberately diminished my contributions – he was a decent man, and he supported my work. But structures of credit in science favour senior, male researchers. Women collaborators become absorbed into their supervisors’ legacies.

What bothers me more is when work I did independently – the 1968 preservation paper, the triradial organisms, the Queensland vertebrates – gets attributed vaguely to “Glaessner’s team” or “Adelaide researchers” without naming me. That’s not about collaboration; that’s about erasure.

In 2016, eleven years after you died, the Association of Australasian Palaeontologists established the Mary Wade Prize for best early-career researcher publication. What does that commemorative gesture mean to you?

It’s kind, and I appreciate that my colleagues remembered me. But there’s an interesting contradiction there, isn’t there? They know my name well enough to put it on a prize, but many recipients probably don’t know what I actually discovered. The name becomes a symbol without content – recognition divorced from understanding of the work itself.

I’d prefer people read the 1968 paper. Understand the waterbed hypothesis. Look at Skinnera and Hallidaya specimens. Know that a woman figured out how Earth’s earliest animals turned to stone, and that insight enabled a half-century of subsequent research.

You saw contemporary researchers – Mary Droser, Jim Gehling, Diego García-Bellido – build careers studying Ediacaran organisms at Nilpena. How do you feel about their work?

Thrilled. Mary’s work excavating those bedding planes at Nilpena is extraordinary – she’s essentially revealing entire seafloor communities, snapshot ecosystems from 550 million years ago. Jim continued the taphonomic investigations I began, adding chemical and microstructural data I couldn’t access in the 1960s. Diego’s morphological and phylogenetic analyses are far more sophisticated than anything I could have done.

That’s what you want – for your work to become foundation upon which others build. My frustration isn’t with contemporary researchers; it’s with the historical narratives that skip from Sprigg and Glaessner directly to Droser and Gehling, as if the 1960s-70s preservation framework materialised spontaneously.

What mistakes did you make? Where were you wrong?

I underestimated the diversity of taphonomic modes. I thought the resistant/non-resistant division was fairly clean, but we now know there’s much more variability – some organisms preserved via early silica cementation, others via pyrite, still others via clay mineral authigenesis. My framework was too binary.

I also probably overinterpreted some of the triradial organisms as cnidarians – jellyfish relatives. With hindsight and better phylogenetic tools, they’re likely more basal, possibly stem-group metazoans or even something outside crown-group animals entirely. Taxonomic assignments were premature.

And I didn’t push back hard enough against the institutional structures that limited my career. I accepted the demonstrator position, accepted the collaborative framing, accepted that museum curators occupied lower prestige than university professors. A younger generation of women scientists has been less willing to accept those constraints, and good for them.

What advice would you give to young women in palaeontology today?

Claim your work. When you make a discovery, when you develop a new method, when you solve a problem – put your name on it. Don’t defer to supervisors, don’t hide behind collaborative “we,” don’t accept being listed second when you did the primary intellectual labour.

Build relationships, but not at the expense of individual recognition. I built extensive networks across Queensland, which enabled major discoveries. But much of that work is credited institutionally to “Queensland Museum” rather than to me personally. Make sure your contributions are individually visible.

And write clearly, write accessibly, write for future generations. My 1968 paper has been cited hundreds of times because it explained mechanisms simply and thoroughly. That kind of foundational writing outlasts you.

Finally: Why does it matter that people remember Mary Wade?

Because women’s intellectual labour – especially explanatory, infrastructural labour – disappears too easily from scientific memory. Men discover fossils and get their names on them. Men propose grand evolutionary theories and get remembered for frameworks. Women often do the patient work of figuring out how and why – the mechanisms, the methods, the careful observations that make everything else possible.

I spent months in the Flinders Ranges, examining bedding planes, distinguishing resistant from non-resistant organisms, working out sediment movement through microbial mats. That work enabled half a century of Ediacaran research. But popular accounts talk about “the Ediacaran Biota” and “Earth’s first animals” without mentioning the woman who explained how they could possibly fossilise at all.

It matters because it’s still happening. Women are still doing the infrastruct Ediacara ural work, still getting absorbed into collaborative credits, still seeing their insights attributed to teams or institutions rather than individuals. If we can’t remember women who did foundational work a generation ago, how will we remember the women doing it now?

I solved the preservation puzzle. I explained how Earth’s first animals turned to stone. I named new organisms, excavated dinosaur trackways, built museum collections, trained students and volunteers. That work deserves to be remembered, attached to my name, not dissolved into vague institutional narratives.

Thank you, Dr Wade. This has been illuminating.

Thank you for asking. And please – when you write about the Ediacara Biota, cite Wade 1968. It’s in Lethaia, Volume 1, pages 238-267. The mechanisms are all there.

Letters and emails

Following our conversation with Dr Wade, we received an extraordinary response from readers worldwide eager to learn more about her work and legacy. We’ve selected five letters and emails from our growing community – spanning five continents – whose questions probe deeper into the technical details of her preservation research, the ethics of collaborative science, and the choices she faced as a woman in mid-century Australian palaeontology.

Rina Kobayashi, 34, Marine Geologist, Okinawa, Japan
You mentioned that microbial mats were crucial to Ediacaran preservation – acting as both substrate and sealing membrane. In your fieldwork at Ediacara, what direct evidence did you observe that confirmed microbial mat presence? Were there specific sedimentary structures, geochemical signatures, or textural features in the sandstone that distinguished mat-bound surfaces from ordinary mudflats? I’m curious whether techniques available in the 1960s allowed you to identify fossilised biofilm remnants, or whether your interpretation was primarily inferential from the preservation patterns themselves.

Rina, that’s an excellent question, and it gets right to the heart of the inferential challenge we faced in the 1960s. The short answer is: my interpretation of microbial mat involvement was primarily inferential, based on preservation patterns and sedimentological context, because we simply didn’t have the analytical tools to identify fossilised biofilm remnants at the cellular or molecular level.

Let me walk you through what I actually observed in the field at Ediacara. When you’re examining these Precambrian sandstone surfaces – the Rawnsley Quartzite, specifically – certain features immediately stand out. First, the fossils occur preferentially on specific bedding planes, not randomly distributed throughout the formation. They’re concentrated at interfaces between finer and coarser sediments, suggesting these surfaces had special properties that both attracted organisms and facilitated preservation.

Second, the bedding planes themselves often showed a peculiar texture – what we’d call “wrinkle marks” or “elephant skin” texture. These are sinuous, anastomosing ridges and furrows, typically a few millimetres in relief, that look nothing like ordinary ripple marks or other inorganic sedimentary structures. Martin Glaessner and I both recognised these as likely microbial mat surfaces, analogous to modern stromatolitic textures. They indicated that the seafloor wasn’t just bare sand; it was stabilised by biological films.

Third – and this was crucial to my waterbed hypothesis – the counterpart casts showed evidence of sediment mobility after initial deposition but before full lithification. The casts weren’t simply sediment that had settled into voids from above; they showed injection features, pressure ridges, and in some cases, you could see how sediment had been forced upward through discrete pathways. That kind of focused fluid or sediment movement through an otherwise stable surface strongly suggested a semi-permeable membrane – the microbial mat – controlling where and how sediment could move.

Now, could we see actual fossilised bacteria or biofilm organic matter? Not with the techniques available to me in the 1960s. We didn’t have scanning electron microscopy in routine use for palaeontological work. We certainly didn’t have the geochemical analytical methods – carbon isotope analysis, lipid biomarkers, that sort of thing – that might have detected chemical signatures of microbial activity. I was working with hand lenses, binocular microscopes, field observations, and careful description.

There were occasional thin carbonaceous films on some bedding planes – dark organic-looking residues – but whether these represented actual preserved biofilm material or later diagenetic staining was impossible to determine definitively. I noted them, described them, but couldn’t prove their biological origin.

So my reasoning was essentially this: modern microbial mats stabilise sediment surfaces, create distinctive textures, and can seal substrates sufficiently to trap fluids and allow pressure-driven sediment movement. The Ediacaran bedding planes showed those textures. The preservation required rapid burial followed by sediment injection from below. Microbial mats provided the most parsimonious explanation linking those observations.

It was inference from function and analogy, not direct chemical or microstructural evidence. Adolf Seilacher, when he proposed his “Ediacaran garden” concept in the 1980s, also emphasised microbial mat substrates, but he was making similar analogical arguments. It wasn’t until the 2000s – well after my retirement – that researchers like Jim Gehling started finding pyrite framboids and other microstructural evidence more directly supporting microbial involvement in the preservation process.

I’ll be honest: there were times I wished I could have taken samples back to Adelaide and put them under an electron microscope, analysed organic residues, run experiments with modern cyanobacterial mats to see if they produced similar preservation. But those tools either didn’t exist or weren’t accessible to a demonstrator at a regional Australian university. You worked with what you had – sharp eyes, careful observation, knowledge of modern analogues, and rigorous logical inference.

The strength of the waterbed hypothesis wasn’t that I could prove microbial mats existed; it was that the model explained multiple otherwise-puzzling observations in a coherent framework. That’s often how geological inference works – you can’t run controlled experiments on events 550 million years ago, so you build the best explanatory model from available evidence and test it against new finds.

Tomáš Kováč, 52, Secondary School Science Teacher, Bratislava, Slovakia
When you worked on Ordovician nautiloids from Black Mountain – describing over 200 specimens – you were examining cephalopods that lived roughly 450 million years ago, separated by nearly 100 million years from your Ediacaran organisms. How did shifting between such vastly different geological periods and taxonomic groups affect your interpretative framework? Did studying shelled cephalopods with clear modern analogues change how you thought about the soft-bodied, enigmatic Ediacaran forms? Or did you find that being a “time traveller” across the Palaeozoic and Mesozoic made you more comfortable with uncertainty in the Precambrian?

Tomáš, you’ve identified something I’ve thought about a great deal over the years – how working across such enormous temporal and taxonomic ranges shaped the way I approached palaeontological problems. The honest answer is that it made me both more humble and more methodologically flexible than I might have been had I specialised narrowly in one group or period.

When you’re examining an Ordovician nautiloid – say, one of the specimens from the Black Mountain limestone near Mount Isa – you’re working with an organism that has clear modern relatives. Nautiloids are cephalopods; we have Nautilus swimming about in the Indo-Pacific today. You can reasonably infer soft tissue anatomy, feeding behaviour, mode of life, because you have living analogues. The shells themselves are beautifully preserved, often with intact chambers, siphuncles clearly visible, suture patterns crisp. There’s tremendous morphological detail available.

The interpretative framework is relatively secure. You’re asking questions like: What does this siphuncle morphology tell us about buoyancy regulation? How do chamber spacing patterns correlate with growth rates? Is this species benthic or nektonic based on shell shape and ornamentation? These are tractable questions because you have both excellent preservation and modern comparison points.

Now contrast that with something like Dickinsonia from Ediacara. It’s an oval, quilted, segmented organism roughly 550 million years old with no clear modern analogue whatsoever. No shell, no hard parts, no living descendants we can confidently point to. The preservation is a compressed mould in sandstone – you’re seeing an impression, not the organism itself. You’re inferring three-dimensional morphology from a two-dimensional compression.

The questions you can legitimately ask are far more constrained. Was it even an animal? Probably, but some researchers thought it might be a lichen or fungus. Did it have organs? Possibly, but you can’t see them. How did it feed? Speculation – maybe osmotrophy through its lower surface, maybe photosymbiosis, maybe filter feeding. Was it mobile? The trace fossil evidence suggests yes, but slowly.

Working between these extremes taught me to calibrate my confidence appropriately. With the nautiloids, I could make fairly strong inferences about palaeobiology and palaeoecology. With the Ediacaran organisms, I had to be far more cautious, focusing on what the fossils actually showed rather than what I wished they showed.

But here’s the interesting thing: the nautiloid work made me better at Ediacaran research, not worse. Understanding how modern cephalopods preserve – which tissues decay first, how shells fill with sediment, what taphonomic bias affects size distributions – gave me a framework for thinking about preservation processes generally. When I proposed that Ediacaran organisms preserved differently based on their structural resistance to decay, that insight came partly from observing how different parts of cephalopod bodies preserve differentially.

Similarly, working with trackways – dinosaur footprints at Lark Quarry – taught me to think about substrate properties and how organisms interact with sediment. A theropod running across mud leaves different tracks than one walking across firm sand. That awareness of organism-substrate interaction fed directly into understanding how Ediacaran organisms might have lived on or within microbial mat substrates.

The temporal jumps were intellectually stimulating rather than disorienting. Moving from Precambrian to Ordovician to Cretaceous meant constantly shifting reference frames, but it also meant seeing patterns that specialists might miss. For instance, the importance of storm deposits in creating exceptional preservation – that’s visible in Ediacaran death assemblages, in some Ordovician fossil concentrations, and in Cretaceous marine reptile deposits. The specific organisms differ, but the taphonomic processes show commonalities.

I think being a generalist – or a “time traveller,” as you nicely put it – also made me more comfortable with uncertainty. Ediacaran specialists sometimes tie themselves in knots trying to force these organisms into crown-group animal phyla: this one’s a cnidarian, that one’s an annelid, this must be an arthropod precursor. When you’ve worked with well-understood groups like nautiloids, you recognise how much morphological and anatomical detail you need to make confident phylogenetic assignments. The Ediacaran material simply doesn’t provide that level of detail in most cases.

So yes, I was comfortable saying “I don’t know” about Ediacaran affinities, because I knew what certainty looked like in other contexts. That intellectual honesty – recognising the limits of what fossils can tell you – came from working across the full sweep of geological time rather than burrowing deeply into one narrow interval.

Did it cost me recognition as “the” authority on any particular group? Probably. But it gave me something I valued more: the ability to see deep patterns in how life preserves, how ecosystems respond to environmental change, and how we as palaeontologists should temper our interpretations to match our evidence.

Camila Duarte, 29, Doctoral Student in Taphonomy, São Paulo, Brazil
You described the “waterbed hypothesis” – sediment forced upward through microbial mats creating counterpart casts – as a pressure-driven mechanical process. What physical experiments or field observations convinced you this mechanism was operating, rather than simple sediment infill from above? Did you attempt any analogue experiments with modern sediments and bacterial films to test whether your proposed mechanism was physically plausible? I wonder whether the technical constraints of 1960s laboratory work prevented you from experimental validation, or whether the field evidence was simply so compelling that experiments felt unnecessary.

Camila, you’ve asked about experimental validation, and I appreciate that you’re thinking like a proper experimentalist. The truth is, I never conducted formal analogue experiments to test the waterbed hypothesis. That might seem like an oversight from a modern perspective, but let me explain the constraints and reasoning of the time.

In the late 1960s, experimental taphonomy was barely emerging as a field. Johannes Weigelt had done some foundational work in the 1920s and 1930s on vertebrate decay, but experiments specifically testing soft-tissue preservation mechanisms in marine sediments weren’t standard practice. The equipment and facilities needed – controlled sediment tanks, bacterial culture systems, long-term observation apparatus – simply weren’t available at the University of Adelaide’s Geology Department. We had rock saws, thin section equipment, microscopes. Not experimental mesocosms.

More fundamentally, I’m not sure experiments would have been particularly convincing given what we were trying to demonstrate. To properly test whether microbial mats could seal substrates sufficiently to allow pressure-driven sediment injection, you’d need to recreate conditions that take thousands to millions of years geologically – mat growth, sediment accumulation, compaction, early diagenesis. Laboratory experiments run over weeks or months wouldn’t capture those long-term processes.

What convinced me the waterbed mechanism was physically plausible came from field observations at multiple scales. First, the direct evidence on the bedding planes themselves. When you examine counterpart casts carefully – and I spent hours doing this with a hand lens – you can see flow structures. The sediment that formed the cast isn’t homogeneous; it shows subtle laminations, grain size variations, even occasional cross-cutting relationships that indicate it moved upward through the mat rather than settling downward into a void.

Second, the spatial distribution of casts relative to moulds. If casts formed simply by sediment falling into voids from above, you’d expect them to be slightly smaller than the moulds due to compaction. Instead, many counterpart casts are the same size or occasionally larger than their corresponding moulds. That size relationship makes sense if the cast formed by sediment being squeezed upward under pressure – the flexible mat membrane could bulge slightly, creating a cast that precisely matches or even slightly exceeds the mould’s dimensions.

Third, the preferential preservation on certain surfaces. Storm deposits at Ediacara are event beds – relatively thick sandstone layers deposited rapidly. But not every storm bed has fossils. The ones that do typically show those “elephant skin” wrinkle marks I mentioned earlier, indicating mat-covered surfaces. Beds without wrinkle marks rarely preserve Ediacaran organisms, even when the sedimentology is otherwise similar. That correlation between mat indicators and fossil preservation was powerful circumstantial evidence.

Fourth, modern analogues – not experimental, but observational. In the 1960s, researchers studying modern tidal flats and lagoonal environments had documented how microbial mats behave. They’re cohesive, flexible, and can trap sediment and water beneath them. If you’ve ever walked on a modern cyanobacterial mat – which I did in Spencer Gulf during field trips – you feel that waterbed-like response. Step on it, and adjacent areas bulge upward slightly. The mat redistributes pressure laterally rather than simply compressing downward.

Now, could I prove definitively that this was the mechanism? No. But the convergence of evidence – the flow structures in casts, the size relationships, the correlation with mat indicators, the behaviour of modern mats – made it the most plausible explanation available.

I also want to address something implicit in your question: the assumption that experimental validation is necessary or even superior to field-based inference. In geology generally, and palaeontology particularly, we’re often reconstructing processes that occurred under conditions we can’t replicate experimentally. You can’t recreate Precambrian ocean chemistry in a laboratory. You can’t grow a 550-million-year-old microbial mat. What you can do is observe the geological record meticulously, compare it to modern processes where analogues exist, and build mechanistic models that explain your observations.

Adolf Seilacher, whose work I greatly respect, took a similar approach with his Ediacaran research. He didn’t run experiments; he observed patterns in the fossils and sediments, compared them to modern trace-making and bioturbation, and proposed models based on that synthesis. That’s classic geological reasoning – uniformitarian principles applied carefully.

If I were starting that research today, with access to modern scanning electron microscopy, X-ray computed tomography, geochemical analytical tools, would I approach it differently? Certainly. I’d look for microbial biomarkers, examine sediment fabric at the microscale, perhaps even attempt decay experiments with modern soft-bodied organisms on mat substrates to see what kinds of moulds form. But those tools didn’t exist in my toolbox in 1968.

The field evidence was compelling enough to convince me, and apparently compelling enough that the waterbed model has remained influential for over fifty years. Sometimes that’s the best validation you can get – when subsequent researchers find your framework useful for interpreting new discoveries.

Jason Rivera, 38, Environmental Consultant, Denver, Colorado, USA
If you could rewrite your career trajectory – knowing what you know now about how institutional structures erased women’s contributions – what would you have done differently in 1959 when you finished your PhD? Would you have left Australia entirely for a North American or European institution where advancement might have been possible? Fought harder for a lectureship at Adelaide? Or do you think the structural barriers were so entrenched that individual resistance would have been futile, and the museum path was genuinely the best available option? I’m trying to understand whether you see your story as one of missed opportunities or constrained optimisation within impossible circumstances.

Jason, that’s a brutally honest question, and I respect you for asking it directly. You’re essentially asking whether I made the right choices, or whether I should have fought harder against structures that I knew were designed to exclude me. It’s something I’ve wrestled with for decades.

Let me start with the hard truth: in 1959, when I finished my PhD, there were essentially no women professors in Australian geology departments. Dorothy Hill at Queensland was the singular exception – she’d gotten her foot in the door in the 1930s before the barriers fully solidified, had Cambridge credentials, and even then faced enormous resistance. For women coming through in the 1950s, the academic pathway was effectively closed.

Could I have left Australia? Possibly. But remember, this was 1959. Married women couldn’t even get passports without their husband’s consent until the mid-1960s. I was unmarried, so that wasn’t my constraint, but international academic mobility for women was extremely limited. The American universities were hardly more welcoming to women faculty than Australian ones. Britain might have been slightly better, but positions were scarce and competition fierce.

More practically, I had no independent financial resources for such a move. My family wasn’t wealthy – my father had various positions around rural South Australia, we’d moved to Thistle Island when I was young because of his work. I didn’t have family connections or substantial savings that would have allowed me to gamble on overseas opportunities. The demonstrator position at Adelaide was secure employment, which mattered when you’re entirely self-supporting.

Could I have fought harder for a lectureship at Adelaide? Here’s where I perhaps made a strategic error. I was too accommodating, too willing to accept that “this is just how things are.” When Martin would suggest I work on the Ediacaran material, I said yes because it was interesting research, but I should have demanded co-equal status on publications from the beginning. When the Department consistently passed me over for lectureships, I should have raised formal complaints, documented the discrimination, made them justify their decisions publicly.

But you have to understand the culture of the time. Women who complained were labelled “difficult,” “uncollegial,” “not team players.” Once you got that reputation, doors closed completely. There was enormous pressure to be grateful for whatever opportunities you were given, to prove you could fit in by not making waves.

I chose survival over confrontation, and that had costs. By staying as a demonstrator for twelve years, I became typecast as a teacher rather than a researcher in the broader academic community’s perception. When I finally moved to Queensland Museum, I was starting over in terms of building an independent research reputation at age 43.

The museum pathway wasn’t second-best, though – that’s important to understand. Museum curators in the 1970s had genuine research opportunities, extensive collections, fieldwork funding. Alan Bartholomai at Queensland Museum was supportive of my research in ways the university never had been. I published prolifically, supervised students, built international collaborations. The work I did on Queensland’s fossil vertebrates, on Lark Quarry, on the Cretaceous marine reptiles – that was world-class research that wouldn’t have been possible from a university demonstrator position.

What I regret isn’t choosing the museum path – it’s accepting the university constraints for so long without sufficient resistance. If I could advise my younger self, I’d say: document everything, demand equal credit, apply for positions you’re “not qualified” for, and don’t internalise their limitations as your own inadequacies.

But I want to push back against the premise of your question slightly. You’re asking whether individual resistance could have overcome institutional barriers, and I think that misses the point. The barriers weren’t accidents or oversights; they were designed features of the system. Dorothy Hill succeeded partly through exceptional talent, but also because she navigated a particular historical window – she established herself before the post-war backlash pushed women out of professional roles.

One woman fighting harder wouldn’t have changed those structures. What changed them was collective action – women’s liberation movements, anti-discrimination legislation, cultural shifts that made excluding women professionally and socially unacceptable. I was part of the generation that bore the brunt of those barriers, but also helped document their existence and cost.

The productive question isn’t whether I should have fought harder, but whether the work I managed to accomplish under constrained circumstances contributed meaningfully to knowledge and to creating opportunities for subsequent generations. I believe it did. The preservation mechanisms I described, the fossil collections I built, the networks I established, the students I mentored – that infrastructure outlasted the discriminatory structures that limited my formal recognition.

In the end, I optimised as best I could within impossible circumstances. That’s not a failure; it’s resilience. And perhaps that’s the more useful lesson for young women today: sometimes the path forward isn’t breaking down the door, but finding alternative routes that let you continue doing the work you love.

Ifeoma Balogun, 41, Science Policy Advisor, Lagos, Nigeria
You built extensive networks with Queensland station owners and amateur collectors, creating what sounds like a genuinely collaborative, community-based research model decades before “citizen science” became a formal framework. How did you navigate issues of intellectual property, authorship, and credit when locals made significant discoveries? Did you ensure that people like Glen Seymour at Lark Quarry or the Hughenden station owners received formal recognition – co-authorship, acknowledgements, naming rights – or did institutional structures make that difficult? I’m interested in whether your approach to democratising palaeontology extended to democratising scientific credit, or whether museums and universities still gatekept those forms of recognition.

Ifeoma, you’ve identified a tension in my work that I’m not entirely proud of, though I’m grateful you’re asking the question. Yes, I built collaborative, community-based research networks across Queensland, and yes, I tried to ensure those relationships were respectful and reciprocal. But did I fully democratise scientific credit in the ways those collaborators deserved? The honest answer is: not as much as I should have.

Let me give you specific examples. Glen Seymour, the station manager at Lark Quarry, discovered the trackway site in the 1960s. He recognised it was significant, protected it, contacted authorities. When Tony Thulborn and I excavated and published the work in the late 1970s, Glen was acknowledged in our papers, but he wasn’t offered co-authorship. The reasoning – standard for the time – was that scientific authorship required participation in analysis, interpretation, and writing, not just discovery or fieldwork assistance.

Looking back, that distinction was serving professional gatekeeping more than genuine intellectual contribution. Glen understood the geological context, knew the stratigraphy of his property better than we did initially, and provided crucial logistical support that made the excavation possible. A more equitable approach would have been to invite him into the analytical process, teach him the technical framework, and include him as a co-author. We didn’t do that.

Similarly, when station owners around Winton and Hughenden would ring me about fossil finds – bone weathering out of a creek bank, unusual impressions in sandstone – I’d drive out, assess the material, arrange collection and transport to the Museum. Those individuals received acknowledgements in papers, occasionally specimens were informally named after them or their properties, but rarely formal co-authorship.

There were exceptions. When working with amateur collectors who had genuine expertise – people who’d been systematically collecting and cataloguing material for years – I tried to involve them more substantively. But institutional structures made this difficult. Museum publication policies, journal editorial standards, academic conventions all assumed that authorship belonged to credentialed professionals.

I pushed back against this to some extent. I gave public lectures in rural communities, explaining what we’d found and why it mattered. I ensured that station owners received copies of publications describing material from their properties. When specimens went on display, I included information about who found them and where. But these were acknowledgements, not genuine sharing of scientific credit.

The Queensland Museum, to its credit, had a more inclusive approach than many universities. We had volunteer programs, we trained amateur collectors, we treated community members as partners rather than simply sources of specimens. But partnership without co-authorship is still asymmetrical.

Here’s the uncomfortable truth: I benefited from those power asymmetries. My publication record – which determined my professional advancement, my reputation, my eventual recognition – was built partly on discoveries made by others who received acknowledgement but not authorship. I justified this at the time by thinking I was adding the scientific expertise that transformed raw finds into knowledge. But knowledge production isn’t a one-way street where credentialed experts extract data from communities and return only acknowledgements.

Indigenous Australians, particularly in Queensland, had extensive knowledge of fossil sites. Traditional owners knew where bones weathered out, where trackways appeared after rains, which rock formations contained unusual impressions. That knowledge, built over generations, rarely translated into formal recognition in palaeontological publications. We were extracting intellectual and material resources from Aboriginal lands without adequate compensation or credit.

I’m ashamed to say I didn’t think carefully enough about this during my working years. The 1970s and 1980s were periods of emerging Indigenous rights movements in Australia, but palaeontology as a discipline was slow to grapple with issues of ownership, access, and credit for fossils from Aboriginal lands. We operated under colonial frameworks that assumed scientists had automatic rights to study and remove material.

If I were building those networks today, I’d insist on genuine collaborative frameworks. Co-authorship for significant discoveries, regardless of formal credentials. Training programs that built local expertise rather than extracting specimens. Consultation protocols with Traditional Owners about fossil collection and interpretation. Benefit-sharing arrangements so communities gained economically from tourist interest in sites like Lark Quarry.

Some of these practices have become standard in contemporary Australian palaeontology – the Australian Age of Dinosaurs Museum near Winton, for instance, employs local people, involves Traditional Owners in site management, and shares economic benefits with the community. But those developments came after my retirement.

The paradox is that I experienced erasure of my own contributions – absorbed into Glaessner’s legacy, subordinated to institutional credit – yet I participated in erasing others’ contributions when I was in the position of relative power. Being marginalised doesn’t automatically make you sensitive to how you might marginalise others.

What I can say is that the relationships I built were genuine. People trusted me because I showed up, did the work alongside them, treated their knowledge and observations with respect, and returned to share what we’d learned. That relational foundation was important. But respect without structural change in credit allocation is insufficient.

Your question about democratising palaeontology is crucial. If we’re serious about making science more equitable, we need to rethink authorship conventions, acknowledge diverse forms of expertise, and ensure that communities contributing to research benefit tangibly from that contribution. I started that work, but I didn’t finish it. That’s a task for the next generation.

Reflection

Dr Mary Julia Wade died on 14th November 2005, aged 77, her passing not much noted outside specialist circles. Looking back across the encounter – across her words and memories, the records of her fieldwork, the questions asked by readers – one is left with the impression of an intellect that remained quietly, stubbornly generative even when its achievements were overlooked or attributed to others.

From the start, perseverance wove through every thread of her story: a girl from Thistle Island, South Australia, drawn to the patient investigation of rock and bone, whose path led not to professorial acclaim but to museum halls crammed with vertebrate remains and the sandstones of Ediacara, indented by the world’s first animals. Wade’s ingenuity was never showy – in her own account, it was shaped by necessity and guided by attentive observation, the willingness to work with what tools were at hand. She gave careful thought to preservation, and her insight that microbial mats acted almost as waterbeds, allowing sediments to produce faithful casts of ancient life, was both technically profound and imagistically vivid.

But it was the theme of occlusion – how women’s explanatory labour becomes water in the foundations – that ran deepest. In her reflections, Wade does not slide into resentment; she names the circumstances plainly. Largely absent from the citations, her methods absorbed, her framework attributed to more visible men or institutions. Yet she was not simply content to recount erasure; she pressed readers to interrogate it, to see the patterns that afflicted not just herself but her peers – those who, like Dorothy Hill, managed brief openings into academic posts, or others whose field discoveries opened doors for institutions but not for themselves.

Wade’s perspective sometimes sharpens, sometimes softens where the record is ambiguous. She is less romantic about her fieldwork than some accounts, frank about the physical and emotional drain, the heat and uncertainty, the slow accrual of recognition that museum posts afforded. Her account of democratising discovery – embracing station owners, amateur collectors – counters the more institution-centric histories and prompts new understanding of how collaborative networks can either distribute or concentrate credit. If there is an undertone of regret, it is not for the choice of museum or teaching over university, but for the moments when authorship and expertise were not fully shared with those who made discovery possible.

On gaps and uncertainty, Wade remains forthright. Her technical explanations recall that evidence rarely neatly resolves old debates – the challenge of reconstructing Ediacaran life from mere impressions sounds as potent today as in the 1960s. She acknowledges where her own interpretations may have faltered, where modern geochemistry, imaging, or experiment could have fortified, or perhaps even overturned, her explanations.

Today, palaeontology and geology – whether through Precambrian microfossils, Ordovician cephalopods, dinosaur ichnology, or marine reptile studies – continue to benefit from Wade’s foundational insights. The waterbed hypothesis, wrinkled surfaces, taphonomic groupings – these remain living tools in the kit of modern researchers. That her work resurfaced in the hands of Jim Gehling, Mary Droser, Diego García-Bellido, and others, that the Mary Wade Prize now supports early-career scientists, is testament to her framework’s endurance. Each rediscovery, each citation, is both a reminder of her impact and the hazards of historical omission.

In considering her legacy, the lesson is not simply to remember Mary Wade’s name but to understand the cost of invisibility – to ensure the next generation of scientists, especially young women, are not seized by the same shadows. The encouragement she offers is measured: claim your work, build ties that amplify rather than reduce personal recognition, write plainly and generously for those who follow. In Wade’s life, the flame of curiosity and care survived neglect; in her words, the call to resilience and visibility is neither resentful nor complacent but hopeful and grounded.

Her story does not close with bitterness. It closes as a quiet challenge – an intellectual spark – urging readers, researchers, and institutions to ask who is truly seen when knowledge endures, and to make space for those whose careful, ingenious labour lies just beneath the surface.

Who have we missed?

This series is all about recovering the voices history left behind – and I’d love your help finding the next one. If there’s a woman in STEM you think deserves to be interviewed in this way – whether a forgotten inventor, unsung technician, or overlooked researcher – please share her story.

Email me at voxmeditantis@gmail.com or leave a comment below with your suggestion – even just a name is a great start. Let’s keep uncovering the women who shaped science and innovation, one conversation at a time.

Editorial Note: This interview is a dramatised reconstruction created for educational and commemorative purposes. Dr Mary Julia Wade passed away in 2005, and the conversation presented here is entirely fictional. Her responses have been carefully constructed using historical records, published scientific papers, biographical accounts, museum archives, and contemporary research on Ediacaran palaeobiology and Australian geology. Where gaps exist in the documented record, responses reflect plausible perspectives consistent with Wade’s known work, the scientific culture of her era, and the institutional constraints faced by women scientists in mid-twentieth-century Australia.

Some technical details, personal reflections, and anecdotes have been imagined to create a coherent narrative voice, though all scientific contributions, career milestones, and institutional challenges discussed are grounded in verifiable historical sources. The supplementary questions from international readers are likewise fictional devices designed to explore aspects of Wade’s work and legacy that warrant deeper examination.

This reconstruction aims not to replace scholarly biography but to render visible a scientist whose foundational contributions to understanding Earth’s earliest complex life have been inadequately recognised. Readers interested in Wade’s actual publications should consult her 1968 paper in Lethaia and subsequent work on Queensland’s fossil record.

Bob Lynn | © 2025 Vox Meditantis. All rights reserved.