07392 - Top Rare 2.03 Inch Micraster (Heart Urchin) Upper Cretaceous Dyrosaurus phosphaticus belongs to the Cretoxyrhinidae family

belongs to the Cretoxyrhinidae family

anoxic substrates without oxygen

The tooth is in a worse state of preservation

Sister taxa: Cimolichthys

07392 - Top Rare 2.03 Inch Micraster (Heart Urchin) Upper Cretaceous Dyrosaurus phosphaticus belongs to the Cretoxyrhinidae familyWell preserved specimen. Micraster, Agassiz 1836 (heart urchin) Echinoidea Spatangoida Micrasteridae PaleoDB taxon number: 33430 Parent taxon: Micrasteridae according to A. G. Fischer 1966 See also Djabarov 1964 and Sepkoski 2002 Sister taxa: Brissopneustes, Cyclasterinae, Isopneustes, Ovulaster Subtaxa: Micraster (Gibbaster), Micraster (Micraster), Micraster (Plesiaster), Micraster acutus, Micraster americanus, Micraster carinatus, Micraster