Fossil deposit is much richer than expected

January 14, 2019

It has long been known that a quarry near the Dutch town of Winterswijk is an Eldorado for fossil lovers. But even connoisseurs will be surprised just how outstanding the site actually is. A student at the University of Bonn, himself a Dutchman and passionate fossil collector, has now analyzed pieces from museums and private collections for his master's thesis. He found an amazing amount of almost completely preserved skeletons, all between 242 and 247 million years old. The good condition is presumably due to particularly favorable development conditions. These make Winterswijk, which belongs to the so-called Germanic Basin, a cornucopia for paleontology. The study is published in the Paläontologische Zeitschrift.

Jelle Heijne examined exactly 327 remains of marine reptiles for his master's thesis - collected partly from public museums, but primarily from about 20 private collections. He was particularly impressed by the high quality of the finds: "Among them were more than 20 contiguous skeletons," he emphasizes. "Only very few complete skeleton finds are known from the other sites of the Germanic Basin, which stretches from England to Poland."

In his study, the 25-year-old investigated the question of why the bones, which are over 240 million years old, have been preserved so well here. The reason is probably a combination of fortunate circumstances: At that time the Germanic Basin was a sea, which was extremely shallow in today's Winterswijk. This is illustrated by the fossil footprints of terrestrial animals that were found not far from the reptile bones. The region probably resembled today's Wadden Sea of the North Sea coast, but with a bottom that was not sandy but covered in lime silt.

The shallow depth ensured that cadavers quickly hit the ground, where they were then covered by sediment. If dead animals float in the water for a long time and are tossed back and forth by waves and currents, the probability increases that body parts, such as tail, limbs or head, are lost.

Another important factor was a process called "Stick'n'Peel" by paleontologists: The animal is colonized by microorganisms and algae that hold the skeleton together like a skin. "It was probably these two factors in particular that favored the occurrence of well-preserved finds," explains Heijne.

In fact, there is some evidence for the Stick'n'Peel hypothesis. For example, some skeletons lack individual larger bones, while the small bones are complete - even though the latter are usually most likely to be carried away by the water. "Such unusual patterns typically occur when a skeleton is unevenly colonized and thus protected," Heijne explains.

It has long been known that Winterswijk stands out among the sites of the Germanic Basin. Nevertheless, the large number of high-quality finds is likely to surprise even connoisseurs, especially since most of the finds are not accessible to the public. "I have been a member of an association of private collectors in the Netherlands for years," Heijne explains. This was the ideal contact exchange for his study: "The collectors I approached were all proud to be able to contribute to the research on Winterswijk."
-end-
Publication: Jelle Heijne, Nicole Klein and P. Martin Sander: The uniquely diverse taphonomy of the marine reptile skeletons (Sauropterygia) from the Lower Muschelkalk (Anisian) of Winterswijk, The Netherlands; Paläontologische Zeitschrift; dx.doi.org/10.1007/s12542-018-0438-0

Contact:

Jelle Heijne
Institute for Geosciences and Meteorology
University of Bonn
Tel. 0228/73-60058
E-mail: s6jeheij@uni-bonn.de

University of Bonn

Related Paleontology Articles from Brightsurf:

Analysis of volcanic tuff gives new data about Permian-Triassic extinction event
It's not often that scientists are able to find tuff in continental sedimentation, but this was accomplished in the PreUrals region by Kazan Federal University, Borisyak Institute of Paleontology, and Institute of Geology (the latter two are parts of the Russian Academy of Sciences).

Jurassic Park in Eastern Morocco: Paleontology of the Kem Kem Group
The Kem Kem beds in Morocco are famous for the spectacular fossils found there, including at least four large-bodied non-avian theropods, several large-bodied pterosaurs and crocodilians.

Paleontology: Experiments in evolution
A new find from Patagonia sheds light on the evolution of large predatory dinosaurs.

New sphenisciform fossil further resolves bauplan of extinct giant penguins
New Zealand is a key area for understanding the diversity of the extinct penguins and has even revealed the existence of 'giant' penguin species (larger than living penguins).

Superfood for Mesozoic herbivores? Emerging data on extreme digestibility of equisetum and implications for young, growing herbivorous sauropods
The long-necked, big bodied sauropod dinosaurs comprise some of the largest terrestrial vertebrates to walk the earth.

Early dispersal for quadrupedal cetaceans: amphibious whale from middle Eocene
Lead author, Olivier Lambert, Royal Belgian Institute of Natural Sciences, Bruxelles, Belgium, presented the team's findings at this year's annual meeting of the Society of Vertebrate Paleontology held this year in Brisbane, Australia.

Teenage T. rex was already chomping on prey, new UW Oshkosh research shows
New research from the University of Wisconsin Oshkosh indicates that even as a teenager the Tyrannosaurus rex showed signs that it would grow up to be a ferocious predator.

Paleontology: Diversification after mass extinction
A team led by Ludwig-Maximilians-Universitaet in Munich paleontologist Adriana López-Arbarello has identified three hitherto unknown fossil fish species in the Swiss Alps, which provide new insights into the diversification of the genus Eosemionotus.

Dinosaurs put all colored birds' eggs in one basket, evolutionarily speaking
A new study says the colors found in modern birds' eggs did not evolve independently, as previously thought, but evolved instead from dinosaurs.

Fossil turtle didn't have a shell yet, but had the first toothless turtle beak
There are a couple of key features that make a turtle a turtle: its shell, for one, but also its toothless beak.

Read More: Paleontology News and Paleontology Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.