UV Autofluorescence Microscopy of Oklahoma Permian Synapsid Femur (<i>Dimetrodon</i>Cope, 1878) Reveals Blood Clots in Vascular Canals

Abstract: Dimetrodon sp. femur, jaw, teeth, and rib bones were collected at N.E. Frederick, OK, sectioned for histological examination. This Oklahoma Museum of Natural History site has yielded well-preserved Paleozoic fossils decades. All heavily infiltrated with calcite other minerals, yet a reddish-brown mass obstructed many vascular channels. reacted to 374 nm UV illumination by emitting bright blue autofluorescence. was true every specimen indicates heavy presence iron. We conclude that the iron in canals is crystallized remains blood clotted during an asphyxiation event killed animal. Remarkably similar obstructive material also been observed studies performed on bones. these are clots simply await examination under fluorescence.