Hassiacosuchus

Hassiacosuchus
Temporal range: Eocene,
47.8–41.2 Ma[1]
Fossil, State Museum of Natural History Karlsruhe
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauromorpha
Clade: Archosauriformes
Order: Crocodilia
Family: Alligatoridae
Subfamily: Alligatorinae
Genus: †Hassiacosuchus
Weitzel, 1935
Type species
†Hassiacosuchus haupti
Weitzel, 1935

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

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

Alligatoroidea
(stem-based group)
  1. ^ Rio, Jonathan P.; Mannion, Philip D. (6 September 2021). "Phylogenetic analysis of a new morphological dataset elucidates the evolutionary history of Crocodylia and resolves the long-standing gharial problem". PeerJ. 9: e12094. doi:10.7717/peerj.12094. PMC 8428266. PMID 34567843.
  2. ^ Weitzel, K. (1935). "Hassiacosuchus haupti n. g. n. sp., ein durophages Krokodil aus dem Mitteleozän von Messel". Notizblatt des Vereins für Erdkunde und der Hessischen Geologischen Landesanstalt Darmstadt (in German). 16: 40–49.
  3. ^ Mook, C.C. (1941). "A new crocodilian, Hassiacosuchus kayi, from the Bridger Eocene beds of Wyoming". Annals of the Carnegie Museum. 28: 207–220. doi:10.5962/p.330789. S2CID 251510549.
  4. ^ Wassersug, R.J.; Hecht, M.K. (1967). "The status of the crocodylid genera Procaimanoidea and Hassiacosuchus in the New World". Herpetologica. 23 (1): 30–34.
  5. ^ Brochu, Christopher A. (2004). "Alligatorine phylogeny and the status of Allognathosuchus Mook, 1921". Journal of Vertebrate Paleontology. 24 (4): 857–873. doi:10.1671/0272-4634(2004)024[0857:APATSO]2.0.CO;2. ISSN 0272-4634. S2CID 85050852.
  6. ^ Adam P. Cossette; Christopher A. Brochu (2020). "A systematic review of the giant alligatoroid Deinosuchus from the Campanian of North America and its implications for the relationships at the root of Crocodylia". Journal of Vertebrate Paleontology. 40 (1): e1767638. Bibcode:2020JVPal..40E7638C. doi:10.1080/02724634.2020.1767638.