Restoration: Terror of the Oceans

Wesleyan’s remarkable series of fossils casts includes two large specimens of ferocious predatorial reptiles- Plesiosaurus and IchthyosaurusThe fossil casts were in a dishearteningly deplorable state when they were rediscovered, crated in the Penthouse of Exley. The casts were put in crates when the Wesleyan Museum closed in 1957. We did not know where they were stored, but they were moved to the penthouse of the Exley Science center when the building was occupied in 1970. After 60 years of chill and thaw in the uncontrolled environment, large cracks were running across the surfaces, and the paint was chipped in many places. The Ichthyosaurus communis cast even had a number of jarring holes in various places. We probed the possibilities of salvaging these treasures, conducting extensive research into reversible restorative methods.

Being part of the Ward Series of Fossil Casts, this series of early large casts were once celebrated feature exhibits in major museums worldwide from 1866 onwards. Orange Judd donated a full series of these casts to the Wesleyan Museum when it opened in Judd Hall in 1870. The Plesiosaurus macrocephalus was an early cast of the holotype specimen of its species, and the second of its kind to be found. After almost 150 years since their making, the plaster has shrunk from off-gassing and evaporation, causing the inflexible paint layer to peel off and crackle, and simply “floating” above the plaster instead of adhering to it.

As with all the other fossils casts that are out of storage for the first time since 1957, this Plesiosaurus dolichodeirus Ward cast bears the unflattering signs of age- cracked plaster, peeling paint, unidentified stains and a thick coating of 60 year-old dust. (Photo courtesy of Andy Tan ’21)

Given their historical significance, great care was taken to employ the least intrusive methods in their restoration. We strove to minimise the changes made to the original, retaining as much of the old paint as possible. The casts were carefully inspected for unstable paint flecks, which were glued back down using acrylic medium. An airgun was passed gently over the casts to remove dust without abrading the fragile paint layer.

Each speck of missing paint is matched by mixing an identical colour with its adjacent regions from artist acrylics. The paints are then painstakingly stippled onto the plaster. (Photo courtesy of Andy Tan ’21)

A non-shrinking putty was used to fill in the larger holes and cracks in the plaster, some of which were created by early curators nailing labels into the cast itself. The missing paint chips were carefully colour-matched using archival acrylic paints, and filled in using meticulous stippling brushstrokes- a long painstaking process. Artist sponges are used to fill in parts of the background with major blemishes to recreate the natural texture of the casts. As the acrylic paints dry to a finish that looks glossier than the original, distressing of the surrounding matrix was done using fine grit sandpaper buffers, aiming for an earthy texture that is faithful to the original. Each cast took about 20 hours to restore to their formal glory. After applying a thin coat of archival breathable sealant, the casts are ready for show.

Ichthyosaurus platyodon Ward Cast in all its splendour after 30 hours of careful cleaning and restoration. (Photo courtesy of Andy Tan ’21)

Perhaps the modest, undemonstrative splendour of even the most major museums are so ingrained in our minds that we often don’t realise the strenuous effort put into each piece in an exhibition. Perhaps next time, you will take a moment to wonder as you wander, down the galleries of deep time past.

 

Cover photo: Freshly restored Ichthyosaurus communis cast detail from the Joe Webb Peoples Museum collection at Wesleyan. Photo courtesy of Andy Tan ’21.

 

 

 

Hidden Figures

Long thought to be marine dinosaurs,  Plesiosaurs and Ichthyosaurs were once formidable apex predators in the Mesozoic. Living in oceans at the same time when the dinosaurs were roaming the land, these magnificent beasts are now iconic displays in many major museums, showing these animals as representatives of this golden age of the giants, some 228 to 112 million years ago (Ma). Their discovery is a story about an unsung woman of science, whose contribution to palaeontology changed our understanding of evolution forever.

It is a story of heartbreak as well as classist and elitist struggle, which lies behind that innocent, lighthearted children tongue-twister derived from Terry Sullivan’s lyrics to a 1908 song.

She sells seashells on the seashore
The shells she sells are seashells, I’m sure
So if she sells seashells on the seashore
Then I’m sure she sells seashore shells.

The she was Mary Anning (1799-1847),  born poor in southern England, and was never far from the austerity that she internalised as a way of living. Being a woman in the household of a low-class cabinetmaker, Mary had no access to formal education. She did, however, accompany her father in the unusual pastime of fossil hunting along the coast of Lyme Regis, and their fossil finds were sold as curiosities. Neither of her father’s occupations improved the circumstances of the family, and when the father died in 1810, his pregnant wife was left with little more than a large debt.

Mary Anning with her fossil-collecting tools, accompanied by Tray, her dog, on the coast of Lyme-Regis (UK).

It was Mary who found her way in the world by continuing her father’s work in fossil hunting and turning it into a livelihood.With her widowed mother, she managed a little fossil shop  by the sea to eke out a meagre income. In 1811, she made one of the most significant fossil finds in all of history. On the coast of Lyme-Regis, she co-discovered an Ichthyosaurus with her brother – the first of its kind ever to be discovered. This gargantuan specimen was soon purchased by a private collector for £23 (approx. $2200 in today’s worth). In subsequent years, she became the most prolific fossil hunter of her time,  unearthing many other important fossils including Plesiosaurs, Pterodactyls and more Ichthyosaurs, many of which eventually became important holotype specimens.

Mary Anning’s original sketch and notes on a specimen now known as Plesiosaurus dolichodeirus. In spite of her lack of a formal education, Mary taught herself to become proficient in geology, palaeontology and fossil sketching.

Nevertheless, being a working class woman in the 19th-century, Mary never had much credibility in the scientific community. Despite her frequent correspondence with many of its prominent members, and despite providing fossils for their research, she was always the daughter of a cabinetmaker that had no place in scientific discourse. A series of 6 papers starting in 1814 by Sir Everard Home described the Ichthyosaurs based on Mary’s finds, but she was not credited in  the papers. Similarly, in 1821 and 1824, William Conybeare published and presented descriptions of the Plesiosaur fossils and thanked the collector of the fossil, but failed to mention Mary in any way. Even Sir Richard Owen- the scientist who coined the term “dinosaurs”- neglected to mention this lower class woman, despite having thanked the gentleman who acquired it from her, when he described  Plesiosaurus macrocephalus in 1840. So harshly unjust was their negligence of her contributions that she once lamented in a letter “The world has used me so unkindly, I fear it has made me suspicious of everyone.”

Wesleyan’s very own 1970 Ward cast of the Plesiosaurus macrocephalus holotype. From the collection of the Earl of Enniskillen, the original now resides in the British Museum. (Photo courtesy of Andy Tan ’21)

The Plesiosaurs and Ichthyosaurs she introduced to science were the most terrorising predators in the oceans during their heyday. Growing to 15-20m in length and weighing almost a tonne, these monsters were powered by strong flippers that allowed them to pursue their prey at remarkable speeds. Ichthyosaurs were so successful in their survival strategies that they survived for almost 120 million years. By the Cretaceous era, they had adapted to living in every ocean on the planet. Their discovery marked one of the most pivotal moments in palaeontology at a time when the issue of extinction – whether God’s divine creations could possibly become extinct – was a matter of great contention, their discovery was the final testimony that extinctions do occur. When living counterparts of tiny fossil seashells and trilobites may be argued to still be lurking somewhere in the unexplored depths of the ocean, some unfortunate fishermen would almost inevitably have encountered giant swimming lizards should they still inhabit our oceans.

Artist representation of a hunting Plesiosaur- a ferocious predator of the Mesozoic seas.

With contemporaries like Darwin, Charles Lyell and Richard Owen, Mary’s story may have been drowned in the many unjust traditions of scientific publications in the 19th century. Nevertheless, the drama that evolves around her life’s work will live on on Wesleyan’s walls and that of many major museums, as a testimony of science as a field where success in expanding knowledge triumphs over other qualities.

Marvel at the grandeur of these impressive monsters, and listen to their bittersweet tales of toil and tears of an unforgotten giant– Mary Anning. Soon to come, on the 3rd floor of Exley…

 

Cover photo: Ichthyosaurus platyodon skull detail, copy of an original found by Mary Anning,  in the Joe Webb Peoples Museum Collection at Wesleyan University. Photo courtesy of Andy Tan ’21.

Curves: Florida Pliocene Snails

Four millions years is a blink of an eye in terms of evolutionary time.

Our collection houses 5600 specimens of fossil seashells from Sarasota County, Florida, from over 460 species. These fossils are found not along the coast of Florida as one might expect, but buried in sediments far inland. After 4 million years since their demise, their diversity and density still closely resemble that of the rich marine fauna which we see at Florida’s beautiful coasts today.

Florida boasts some of the most prolific shelling beaches, arguably in the entire world. It is home to some of the largest, most exquisite living snails (gastropods), whose shells are highly sought after by avid collectors of nature’s jewels. But among the most prized of all treasures are shells that are  anomalous in their form. Seashells are categorised into two categories based on their body plans: bivalves such as clams, that have two symmetrical shells (left and right), and gastropods, such as snails, which have one shell, commonly   a whorled spire, sometimes a shallow cone. You might not have noticed a rather unusual fact about the coiled snails: almost all  are right-handed, i.e.,  their opening (aperture), where the living fleshy part of the snail emerges from its shell, is on the right when the shell placed in standard position, with the earliest-formed part (the protoconch) pointing up.

Marine snails in standard  position- their protoconches are pointing upwards and their apertures are facing the viewer. Note that the apertures are all on the right side. From left to right: Conus cedonulli, Eustrombus gigas, Murex pecten, Charonia tritonis, Busycon candelabrum.

As said above, the present beaches are not the only place in Florida where one can find shells. Far in-land, in the county of Sarasota, fossil-bearing sediments from the Pliocene contain some of the most abundant and diverse mollusc faunas in the world. Four million years ago, sea levels were much higher than  today. The entire county of Sarasota was covered by a shallow sea teeming with life. Temperature drops in the Pleistocene period, that followed the Pliocene, resulted in more of the ocean waters to be locked up at the poles in the polar ice sheets, and the sea levels fell as a consequence. Over a very short period of time, many shallow seas thus  emerged as land, forming a major part of what we know as Florida today. Marine life died in massive numbers in the inland areas and their harder parts were preserved as fossils—windows into marine diversity of the Pliocene.

In Wesleyan’s collections, even very small specimens are well preserved. Many of these are represented in large numbers (hundreds in some samples) and are kept in glass vials.

Since the Pliocene, marine faunas have adopted their modern configurations. If you walk down the shores in Florida today, you will find very similar shells as those that lived at Sarasota  four million years ago. Some species may have gone extinct, but many speciations occur in continuum with the living shells we have today.  A handful of species might no longer be represented, but many iconic species have changed very little in the millennia since. One enchanting specimen is the lightning whelk, Busycon contrarium Conrad. While most species of snails have a rightward spire, as described above, the lightning whelk and their allies have a sinistral morphology – a leftward spire. This is unique to six whelk species that are endemic to North America (and hence the species name contrarium – the contrary whelk).

Sinistral marine snails of the genus Busycon (whelk) are common in North America since  the Pliocene, and their morphologies have remained superficially similar. The Busycon contrarium on the left lived in the warm Pliocene reefs, whereas Sinistrofulgur perversum (formerly Busycon perversum) is an extant species.

It is not often clear why North American marine snails that evolved sinistrality became so successful in their native habitats. There is some evidence for an evolutionary advantage due to predator evasion; predators are used to attacking snails from their right. Alternatively, this novelty could simply be a random trait that raised from a chance mutation that happens to be selectively neutral—it renders neither advantage nor disadvantage to the snails that carry it. The success of the sinistral snails into the modern days debunks a blatant misconception many hold towards evolutionary theory. In the 18th century, evolution was given the connotation of ‘progress’, a highly goal-driven process in which all things become increasingly more complex and more sophisticated. A model of thought called the Great Chain of Being, having its origin in writings by ancient Greek neoplatonists, was prevalent from medieval times through the 18th century: all animals evolve in a mono-directional upward hierarchy that resembles a ladder with the ultimate goal being apotheosis into humans. Vestigial traditions of this school of thought are still embedded in our society, given its popularity in 18th century Christian interpretive traditions. Even today, the icon of the March of Progress that portrays humanity as the result of a linear progress from apes, is influencing the popular ideas  about evolution as a linear advancement and improvement.

A simplified version of the March of Progress, depicting evolution as synonymous to progress. In truth, evolution is more akin to an experiment that creates many potentially viable products, with a large number of failures.

In gastropods, lefties are not common, even among shells. All of the six known extant sinistral shell species of Busycon whelks in North America  diverged from one lineage – the original B. contrarium. Traits that confer significant fitness often have high levels of convergence in analogous habitats. Given that sinistrality in these North American gastropods only evolved once in the marine environment, the evolutionary advantage of this trait is not clear, and it might be negligible.  In our collection, we are fortunate to feature another sinistral species- Conus adversarius. These unusual species are in high demand by collectors seeking novelties.

As these popular jewels of the natural world still line our shores today, measures are in place to protect their heritage that spanned more than 4 million years of geological time. Legislation in Florida aims to restrict the removal of living shells from their natural habitat, and  to preserve these ancient lineages which originated before the dawn of humans, lest our arrogance and ignorance cause them to disappear from our shores forever.

The origin of Wesleyan’s large collection of Pliocene molluscs from Sarasota, Florida is still undetermined. Some detective work in the archives will be done to track down the provenance of these beautiful specimens.

 

Coauthored by Tan Yu Kai and Andy Tan

Cover photo: Apical view of a Busycon contrarium in the Joe Webb Peoples Museum Collection at Wesleyan University. Photo courtesy of Andy Tan ’21.

 

Introduction to the Joe Webb Peoples Museum

On the Fourth Floor of the Wesleyan Exley Science center is the Joe Webb Peoples Museum, named after the late Professor Joe Webb Peoples, who was chair of the Geology department (now named Earth and Environmental Sciences), from 1935 until his retirement in 1975. He was highly influential in the establishment of Dinosaur State Park when dinosaur footprints were discovered on state land in 1966.

The museum has collections of beautiful minerals (including a large collection of Connecticut minerals), and amazingly preserved fossils. The dinosaurs leaving the footprints roamed around lakes in which is now the Connecticut River valley, about 200 million years ago. Thousands of fish living in these lakes (and insects and plants) were preserved as fossils, and are well represented in the collections at Wesleyan.

In addition, the museum has beautifully preserved fish, leaves and insects from the Eocene Period, when the world was much warmer than today (about 40-45 million years ago). These organisms lived in what is now Utah, Wyoming and Colorado. There are also fossil plants from the coal deposits in Illinois (about 300 million years old), as well as fossil sea lilies (crinoids) which lived in shallow warm seas in what is now Indiana at about the same time as the coal forests grew. Many of these fossils were collected by S. Ward Loper, who was curator of the Wesleyan Museum from 1894 to his death in 1910.

Sadly, few people are aware that Wesleyan has these unique resources. The collections have not been well curated, and not much used in education and outreach.

In this series of blogs we will tell stories about the Wesleyan museum collections, the Wesleyan Museum, and the people who were involved with the museum over the years, and make the Wesleyan community aware of this great resource.

Front view of the skull of a Megacerops, better known by the synonym of Brontotherium. This is the skull of a very large herbivore (up to 14 ft in length, 8 ft  shoulder height), browsing on low-growing vegetation, living on the North American continent in the Eocene period.  These animals became extinct when global climate cooled at the end of the Eocene.            This specimen was collected in 1889 by Yale Professor O. C. Marsh in the White River badlands of South Dakota, and bought by the Wesleyan Museum in 1929.

 

posted by Ellen Thomas

Research Professor in E&ES, University Professor in CIS