History Asterotrygon

fossils of asterotrtygon found in fossil butte, wyoming.

before description of asterotrygon, heliobatis known stingray in green river formation. american paleontologist othniel charles marsh named heliobatis radians in 1877, , xiphotrygon acutidens , palaeodasybatis discus subsequently named formation in 1879 , 1947, respectively. these stingrays later synonymized heliobatis.

in 1980, green river fossil called amnh p 11557 described included female stingray , 2 smaller individuals thought aborted fetuses. second specimen called fmnh pf 15166 included female , fetus still in embryo within animal. genus asterotrygon erected in 2004 along type species a. maloneyi, , fmnh pf 15166 designated holotype specimen. amnh p 11557 , many other complete fossils referred a. maloneyi. hundreds of fossils of heliobatis have been found, while asterotrygon represented few dozen specimens. asterotrygon means star stingray greek asteros ( star ) , trygon ( stingray ) after star-like shape of base of each denticle. type species a. maloneyi named after thomas maloney, donated paratype specimen amnh p 11557 american museum of natural history.

although asterotrygon not earliest stingray (they present early cretaceous, 1 of well-preserved of forms. earlier stingrays known small teeth, dermal denticles, or stingers, not entire bodies.