IMAGE: An interesting reconstruction of the hybodontiform shark Asteracanthus; for scale see silhouettes at the view on the lower right hand corner more
Cliu: © Sebastian Stumpf / Fabrizio De Rossi
In a new study, an international research team led by Sebastian Stumpf from the University of Vienna describes a well-preserved skeleton of the ancient shark Asteracanthus. This very rare fossil find comes from the famous Solnhofen limestone in Bavaria, which was formed in a subtropical low-tropical landscape in late Iraq, about 150 million years ago. The almost complete skeleton shows that Asteracanthus was two and a half meters in life, which makes this ancient shark one of the largest of all time. The study is published in the journal Papers in Palaeontology.
Cartilaginous fibrosis, which includes sharks and rays, is one of the most successful skeletal groups still alive today. As a result of their lifelong tooth decay, cartilaginous fish teeth are among the most commonly found fossil vertebra. However, the low retention capacity of the cartilaginous skeletons prevents fossil sampling that is completely preserved in most cases. Thus very rare retention of cartilaginous fish skeleton is associated with specific conditions at fossil time and is limited to a few fossil-only areas.
Solnhofen limestones in Bavaria, Germany, formed in the late Jurassic, about 150 million years ago, are so rare. They are world-renowned for making the skeleton of the small feathered dinosaur Archeopteryx and have donated a number of shark skeletons and rays, which have been recovered through excavation over the past 150 years. New study published in the journal Papers in Palaeontology and led by paleontologist Sebastian Stumpf from the University of Vienna presents the largest fossil shark skeleton ever found in Solnhofen limestone. The sample is represented by an almost completely preserved skeleton of the extinct hybodontiform shark Asteracanthus, and the total length was two and a half meters in life, making it a giant among Jurassic sharks.
Hypbodontiform sharks, which are most closely related to modern-day sharks and rays, appeared during the latest Devonian, about 361 million years ago, and became extinct with dinosaurs in the late Cretaceous, about on 66 million years. They had two dorsal fins, each supported by a dorsal spine. The body size of hybodontiform sharks ranged from a few centimeters to about three meters in length, which in turn makes Asteracanthus one of the largest representatives of both its body and its timing. In contrast, modern-day sharks and rays, which were already diversified through the Jurassic, only reached body size up to two meters long in rare cases.
Asteracanthus was scientifically described over 180 years ago by the Swiss naturalist-Louis Louis Agassiz on the basis of the posterior spikes of an isolated fossil spine. However, arctic skeletal remains have never been found – to date. The teeth of the skeleton are well preserved and contain over 150 teeth, each with a moderately developed cusp that has several smaller cones on each side. “This type of specialist dentistry suggests that Asteracanthus was an active predator feeding on a wide range of predators. Asteracanthus was certainly not only one of the largest cartilaginous fish of its time, but also one of the greatest cartilaginous fish of its time, but also one of the most impressive. “said Sebastian Stumpf.
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Published in Papers in Palaeontology: Stumpf, S., López-Romero, FA, Kindlimann, R., Lacombat, F., Pohl, B. & Kriwet, J. 2020. A unique hybodontiform skeleton gives us new insights into Mesozoic chondrichthyan life. Papers in Palaeontology.
DOI: https: /
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