Severn Formation

The Severn Formation is a Mesozoic geologic formation in Maryland. Dinosaur remains diagnostic to the genus level are among the fossils that have been recovered from the formation.

Dinosaurs

 * "Coelosaurus" antiquus
 * Ornithomimidae indet.
 * Hadrosauridae indet.

Plesiosaurs

 * Cimoliasaurus magnus

Mosasaurs

 * Halisaurus platyspondylus
 * Prognathodon rapax
 * Mosasaurus hoffmanni
 * Mosasaurus sp.
 * cf. Mosasaurus conodon
 * Mosasauridae indet.

Crocodylomorphs

 * Deinosuchus rugosus
 * Thoracosaurus neocesariensis
 * Alligatorinae indet.

Turtles

 * Peritresius ornatus
 * Osteopygis emarginatus
 * Trionyx priscus
 * Toxochelyidae indet.

Chondrichthyans

 * Carcharias holmdelensis
 * Carcharias samhammeri
 * Chiloscyllium greeni
 * Cretalamana appendiculata
 * Dasyatis sp.
 * Tomewingia problematica
 * Galeorhinus garadoti
 * Ginglymostoma sp.
 * Heterodontus sp.
 * Hybodus sp.
 * Ischyrhiza cf. avonicola
 * Ischyrhiza mira
 * Myliobatis sp.
 * Odontaspis aculeatus
 * Plicatoscyllium antiquum
 * Plicatoscyllium derameei
 * Pseudohypolophus mcnultyi
 * Ptychotrygon vermiculata
 * Raja farishi
 * Rhinobatos sp.
 * Rhombodus binkhorsti
 * Serratolamna serrata
 * Squalicorax kaupi
 * Squalicorax pristodontus
 * Squatina hassei
 * Ischyodus sp.

Osteichthyans

 * Albuidae indet.
 * Anomoedus cf. haseolus
 * Cylinadracanthus sp.
 * Egertonia sp.
 * Enchodus ferox
 * Hadrodus sp.
 * Lepidosteus sp.
 * Paralbula casei