Hassiacosuchus

Hassiacosuchus is an extinct genus of small alligatorid from the early Eocene of Germany, found at the Messel pit. It was named in 1935 by K. Weitzel, and the type species is H. haupti.^[2] A second species, H. kayi, was named in 1941 by C.C. Mook for material from the Bridgerian (early Eocene) of Wyoming,^[3] but was reassigned to Procaimanoidea in 1967 by Wassersug and Hecht.^[4] Hassiacosuchus may be the same as Allognathosuchus; Christopher Brochu has recommended continuing to use Hassiacosuchus.^[5]

Specimen at the Natural History Museum of Basel

Hassiacosuchus Temporal range: Eocene, 47.8–41.2 Ma[1] PreꞒ Ꞓ O S D C P T J K Pg N
Fossil, State Museum of Natural History Karlsruhe
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Archosauria
Order:	Crocodilia
Superfamily:	Alligatoroidea
Family:	Alligatoridae
Subfamily:	Alligatorinae
Genus:	†Hassiacosuchus Weitzel, 1935
Type species
†Hassiacosuchus haupti Weitzel, 1935

The cladogram below from the 2020 Cossette & Brochu study shows the placement of Hassiacosuchus within Alligatoridae:^[6]

Alligatoroidea	Leidyosuchus† Deinosuchus† Diplocynodontinae† Diplocynodon† Alligatoridae Caimaninae (stem-based group) Alligatorinae Ceratosuchus† Hassiacosuchus† Navajosuchus† Allognathosuchus† Alligator mcgrewi† Alligator prenasalis† Wannaganosuchus† Arambourgia† Procaimanoidea† Alligator olseni† crown Alligatorinae (stem-based group) (crown group)
(stem-based group)