Proteothrinax is a frilled shark from the Late Cretaceous-Miocene of Austria, Canada, Antarctica, Angola, New Zealand, and Ecuador. It was named in 2012 by Friedrich H. Pfeil. It was one of the most successful sharks of all time, even happening to be a disaster taxon; as well as this, many species within its genus were once thought to be species of the modern frilled shark genus Chlamydoselachus (this was especially the case for "Chlamydoselachus goliath", one of the largest frilled shark species) before finally being moved to their own genus.[1]
Physiology[]
Not much is known about how Proteothrinax looked, but based on how similar its teeth were to the modern frilled shark, it can be assumed that it looked very similar, having an elongated, serpentine body, rounded pectoral (arm) and pelvic ("leg") fins, long, ribbon-like dorsal (back) and anal (rear) fins, a moderately long, pointed caudal (tail) fin, and a small, elongated head with large jaws; as well as this, it would have had 6 gills located near the head on each side of its body, all of which protruded outwards to form a frilled edge. Its body would have been covered in scaly skin.
Diet[]
Proteothrinax was a predator, preying on cephalopods, smaller sharks, and small fish. Its jaws had nearly 30 rows of small, triple-pronged teeth, which would have been used to get a hold of struggling prey; in fact, some Proteothrinax species had larger and stouter teeth, which allowed them to take on tougher prey than average.
Ecology[]
So far, all we know about Proteothrinax is that, similarly to the modern frilled shark, it may have been a slow-moving ambush predator that struck at its prey like a snake, using the wide gape of its long jaws and its multiple rows of triple-pronged teeth to snag them; however, it may have lived in shallower waters than those its modern relative inhabits, and some species may have had larger and sturdier teeth, allowing them to take on larger or harder-bodied prey items.[2]
References[]
- Cappetta, H., Morrison, K., & Adnet, S. (2019, December 10). A shark fauna from the Campanian of Hornby Island, British Columbia, Canada: an insight into the diversity of Cretaceous deep-water assemblages. Journal of Vertebrate Paleontology. https://www.tandfonline.com/doi/abs/10.1080/08912963.2019.1681421.
- Consoli, C. P. (2008, June). A rare Danian (early Paleocene) Chlamydoselachus (Chondrichthyes: Elasmobranchii) from the Takatika Grit, Chatham Islands, New Zealand. Journal of Vertebrate Paleontology. https://www.tandfonline.com/doi/abs/10.1671/0272-4634%282008%2928%5B285%3AARDEPC%5D2.0.CO%3B2.