An international team of paleontologists from Austria and Switzerland has a particularly well-preserved skeleton of Asteracanthus ornatissimus, a species of hybodontiform shark that lived about 150 million years ago (Jurassic period), in the famous limestone of Solnhofen in Germany.
Preliminary life reconstruction of the hybodontiform shark Asteracanthus ornatissimus. Image credit: Sebastian Stumpf / Fabrizio De Rossi.
“Hybodontiform sharks are the closest relative of modern sharks and rays,” said Dr. Sebastian Stumpf and colleagues from the University of Vienna said.
“They first appeared in the latest Devonian, about 361 million years ago, survived two of the five great Phanerozoic mass extinction events, and eventually became extinct at the end of the Cretaceous, about 66 million years ago.”
“These sharks had two dorsal fins, each supported by a prominent spinal column.”
“Their body size ranged from a few centimeters to about 3 m (10 feet) in maximum length, which consequently resulted in Asteracanthus one of the greatest representatives of his group and his time. ”
“In contrast, modern sharks and rays, which were already diverse during the Jurassic, in very rare cases only reach a body size of up to 2 m (6.6 feet) in maximum length.”
Asteracanthus ornatissimus from the Lower Tithonian of Solnhofen, Bavaria, Germany: (A) interpretive line drawing; (B) plate containing sample; (C) a close view of the dorsal spine; (D) close-up view of the dorsal fin fin; (E) provisional reconstruction of the woman Asteracanthus ornatissimus. Abbreviations: adfs – anterior vinvin, af – anal vin, bv – basiventral, cf – caudalvin, ebr – epibranchial, lal – lateral line, Mc – Meckel’s cartilage, nc – neurocranium, notc – notochord, pcf – pectoral vin, pdfs – posterior dorsal vertebra , plr – pleural rib, pq – palatoquadrate, pvf – pelvic fin, scc – scapulacoracoid. Scale bars – 50 cm in (A, B) and 10 cm in (C, D). Image credit: Stumpf et al., doi: 10.1002 / spp2.1350.
In the new investigation, the paleontologists have a new, particularly well-preserved skeleton of investigation Asteracanthus ornatissimus with teeth and finches from the Solnhofen limestones.
‘Asteracanthus was more than 180 years ago scientifically described by Swiss-American naturalist Louis Agassiz on the basis of isolated fossil dorsal fin spines, ”they said.
“However, articulating skeletal remains have never been found so far.”
According to the team, the dentition of Asteracanthus ornatissimus contains more than 150 teeth, each with a well-developed central point accompanied on both sides by several smaller cushions.
‘This specialized type of denture indicates Asteracanthus was an active predator that feeds on a wide variety of prey animals, ‘said dr. Stumpf said.
‘Asteracanthus was certainly not only one of the largest cartilaginous fish of his time, but also one of the most impressive. ”
The findings were published in the journal Papers in paleontology.
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Sebastian Stumpf et al. A unique hibodontiform skeleton offers new insights into Mesozoic chondrichthyan life. Papers in paleontology, published online on January 13, 2021; doi: 10.1002 / spp2.1350