fossils

“Faked” fossils reveal hidden marine reptile diversity

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Franz
Anthony

Editor and Artist
Over 20 specimens of Ichthyosaurus from the 1700s and 1800s were misidentified due to fabricated body parts. A study suggests they belong to a sister genus, Protoichthyosaurus.

Paleontologists today know that a fossil, however incomplete, reveals tiny bits of the past like puzzle pieces of an ancient landscape. But this hasn’t always been the case. A number of dolphin-like marine reptiles called ichthyosaurs discovered in the late 1700s to early 1800s have been spotted with mixed-up body parts, likely an attempt to make them more attractive for display. This old practice wasn’t intended to deceive, but it has led to several cases of mistaken identity.


“Rediscovering” the past through forgotten or mislabeled museum specimens is what Dean R. Lomax from The University of Manchester is known for. By “questioning over and over again” whether the fossils’ parts were genuine or not, Lomax and his colleague Judy Massare from the State University of New York have discovered that at least 20 fossils thought to be Ichthyosaurus actually belonged to a separate yet closely related genus, Protoichthyosaurus.


This genus was actually first identified and scientifically described by Dr. Robert Appleby in 1979. However, his study was dismissed in 1997 because the fossil he studied had one forefin that made it Protoichthyosaurus and one “fake” fin from Ichthyosaurus.


The main difference between the two animals’ fins is subtle for the untrained eyes: they had a different amount of bones. For the animals, it could’ve led to specific ways of maneuvering with their fins, causing them to take different niches or lifestyles. This suggests that the two ichthyosaurs, which shared the Early Jurassic oceans 200-190 million years ago, were much like how a house cat is different from a puma.


What complicates this further is that some Ichthyosaurus specimens had pathological conditions where some of their bones co-ossified, or fused together, making them resemble Protoichthyosaurus. In their study, Lomax and Massare “had to rigorously look at all of their forefins,” including specimens with mixed-up body parts. “When it wasn't a 'fake', we found the co-ossifications,” Lomax stated, referring to the subtle line that marks where the bones fused together.


Adding to this study was Rashmi Minstry, former undergraduate student from University of Reading. While working on her dissertation in 2016, she discovered a juvenile fossil with a fin feature that matched Protoichthyosaurus specimens Lomax was studying in the university’s collections. This specimen is the only known juvenile from this genus to date.


In the collections of The University of Nottingham, Lomax also discovered a single specimen of Protoichthyosaurus unlike the other 20 specimens he studied. Its skull has a notably rounder base which tapers more drastically to its slender snout. As a part of the same study, Lomax and Massare named this fossil Protoichthyosaurus applebyi to honor of Dr. Robert Appleby, who gave the first species the name Protoichthyosaurus prostaxalis in 1979.


Protoichthyosaurus and Ichtyosaurus are part of a lineage of marine reptiles collectively called ichthyosaurs. They swam the seas of the Early Triassic to Late Cretaceous, roughly 248 to 90 million years ago. Although they lived all over the globe, many discoveries of ichthyosaurs happened in and around England where Lomax is based.


Through this study, Lomax and Massare have once again shown that combing through old specimens is just as important as digging up new ones. By applying the latest knowledge and technological innovations, even last century’s bones can tell us new stories.


Reference:
Lomax, D. R., Massare, J. A. and Mistry, R. 2017. The taxonomic utility of forefin morphology in Lower Jurassic ichthyosaurs: Protoichthyosaurus and Ichthyosaurus. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1361433

Image Credit: University of Nottingham - Dean R. Lomax

8e6ac47821297aeee8c843e680637dca

Franz
Anthony

Editor and Artist


http://sulc.us/xdr9m
http://www.eartharchives.org/articles/faked-fossils-reveal-hidden-marine-reptile-diversity/