A new species of ichthyosaur that lived about 200 million years ago has been identified from a fossil found in a quarry in Nottinghamshire, England.
Reconstruction of Wahlisaurus massarae. Image credit: James McKay.
The Nottinghamshire fossil is from the Early Jurassic and only several species of ichthyosaurs are known from this period, making the discovery very significant.
The fossil had been in the collections of Leicester’s New Walk Museum for more than 60 years until University of Manchester paleontologist Dean Lomax spotted unique features.
The specimen is relatively complete, consisting of a partial skeleton including a skull, pectoral bones, limbs, pelvis bones, ribs and vertebrae.
However, the bones are disorderly – it appears that the carcass ‘nosedived’ into the seabed before it became fossilized, which may have restricted previous study.
“When I first saw this specimen, I knew it was unusual. It displays features in the bones – especially in the coracoid (part of the pectoral girdle) – that I had not seen before in Jurassic ichthyosaurs anywhere in the world,” Mr. Lomax said.
“The specimen had never been published, so this rather unusual individual had been awaiting detailed examination.”
“Parts of the skeleton had previously been on long-term loan to ichthyosaur specialist and former museum curator Dr. Robert Appleby, and had only returned to the museum in 2004 after he sadly passed away,” said Dr. Mark Evans, a paleontologist and curator of natural sciences at New Walk Museum.
“He was clearly intrigued by the specimen, and although he worked on it for many years, he had identified it as a previously known species but never published his findings.”
Skull roof elements of Wahlisaurus massarae: A – photograph; B – interpretative illustration based on the preserved skull elements. Due to crushing and damage, some of the sutures are difficult to distinguish. Dashed line indicates a possible suture; diagonal lines indicate a broken edge; grey represents matrix exposed between the bones; black area includes pineal foramen and upper temporal fenestra. Abbreviations: f – frontal; ju – jugal; na – nasal; p – parietal; pf – postfrontal; pif – pineal foramen; po – postorbital; prf – prefrontal; qj – quadratojugal; st – supratemporal. Scale bar – 5 cm. Image credit: Dean R. Lomax.
Mr. Lomax has named the new species Wahlisaurus massarae in honor of paleontologists Prof. Judy Massare and Bill Wahl who have contributed significantly to the study of ichthyosaurs, and who first introduced Mr. Lomax to studying them.
“Both Judy and Bill have been tremendous mentors for me,” he said.
“They have significantly contributed to paleontology, especially the study of ichthyosaurs, and I cannot think of a better way to remember them by naming this new ichthyosaur in their honor. Their names will be set in stone forever, pun intended.”
A research paper describing Wahlisaurus massarae was published online this week in the Journal of Systematic Palaeontology.
According to Mr. Lomax, Wahlisaurus is the first new genus of ichthyosaur from the British Early Jurassic to be described since 1986.
The new species is also important for our understanding of ichthyosaur species diversity, and their geographical distribution during the Early Jurassic.
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Dean R. Lomax. A new leptonectid ichthyosaur from the Lower Jurassic (Hettangian) of Nottinghamshire, England, UK, and the taxonomic usefulness of the ichthyosaurian coracoid. Journal of Systematic Palaeontology, published online June 13, 2016; doi: 10.1080/14772019.2016.1183149
