Paleontologists from the University of Vienna and elsewhere have revised a controversial species of the elasmobranch Protospinax annectans based on new specimens from the Late Jurassic Konservat-Lagerstätte of the Solnhofen Archipelago in Bavaria, Germany.
“The fossil record of sharks and rays (Elasmobranchii) mainly consists of isolated teeth, which are rapidly grown and continuously replaced,” said Dr. Patrick Jambura, a researcher in the Department of Palaeontology at the University of Vienna, and colleagues.
“By contrast, skeletal remains are rare due to the poor preservation potential of the cartilaginous endoskeleton.”
“However, a few localities, so-called Konservat-Lagerstätten, are known to harbor skeletal material with exquisite preservation — sometimes even with soft tissue preservation — and, therefore, offer a unique window into the past.”
“The main Konservat-Lagerstätten for fossil elasmobranchs are several localities in Bavaria, Germany, which are collectively referred to as the Solnhofen Archipelago.”
In the new research, Dr. Jambura and colleagues examined the new fossil skeletal material of Protospinax annectans from the Konservat-Lagerstätte of the Solnhofen Archipelago and revised the skeletal morphology of this species.
“Protospinax annectans carried features that are found in both sharks and rays today,” Dr. Jambura said.
“This species lived some 150 million years ago and was a 1.5-m-long, dorso-ventrally flattened cartilaginous fish with expanded pectoral fins and a prominent fin spine in front of each dorsal fin.”
“Despite the excellent preservation of the previosuly known specimens, its phylogenetic relations with other elasmobranchs have been an enigma since the first description of this species in 1918.”
“Of particular interest is whether Protospinax annectans represents a transition between sharks and rays as a missing link — a hypothesis that has gained considerable appeal among experts over…
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