Dyrosaurus is a genus of extinct crocodylomorph that lived during the early Eocene. The name Dyrosaurus comes from sauros the Greek for lizard or reptile, and Dyr for Djebel Dyr (mountain close to where the type species was discovered.
Species
Although the family Dyrosauridae is quite diverse with many forms of crocodyliforms, the genus Dyrosaurus has only two described species: D. phosphaticus and D. maghribensis. D. phosphaticus was first discovered in Algeria and Tunsinia whereasD. maghribensis has only been found in Morocco. D. maghribensis differs from D. phosphaticus by several synapomorphies, most notably: a smooth dorsal margin of the parietal and widely opened choanae, interfenestral bar wide and strongly T-shaped instead of moderately T-shaped. In D. maghribensis the lateral and medial dorsal osteoderms are not sutured and have no serrated margin. The anterolateral margin of medial row of the dorsal osteoderms have a rounded lateral lobe and the lateral row of dorsal osteoderms are square in shape with rounded corners. In D. phosphaticus there are four longitudinal rows of square osteoderms that are thin and have shallow and wide pits. The osteoderms are square and the anterolateral margin of the medial dorsal osteoderms have an acute rounded process directed laterally.
History of discovery
FrenchpaleontologistAuguste Pomel named the genus Dyrosaurus in 1894 for Djebel Dyr, a mountain near Tebessa in Algeria where its fossilized vertebrae were found in a phosphate mine. The first remains of Dyrosaurus were named Crocodilus phosphaticus by Thomas for Early Eocenecrocodyliform remains from Gafsa, Tunisia. Pomel eventually synonymized the type species D. thevestensis with C. phosphaticus to form the new combinationD. phosphaticus, making phosphaticus the epithet of the Dyrosaurus type species. In 1903, the family Dyrosauridae was named by Giuseppe de Stefano referring to the locality for the holotype was found in Djebel Dyr, Algeria.Thévenin, with some better preserved material, recognized that Dyrosaurus phosphaticus was a Lower Eocene crocodyliform. Many dyrosaurid remains are known, but unfortunately they are often poorly preserved which makes it difficult for paleontologists to get a strong understanding of the family.
