Brochuchus

Brochuchus Temporal range: Miocene
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Superorder:	Crocodylomorpha
Order:	Crocodilia
Family:	Crocodylidae
Clade:	Osteolaeminae
Genus:	†Brochuchus Conrad et al., 2013
Type species
†Brochuchus pigotti (Tchernov & Van Couvering, 1978 [originally Crocodylus pigotti])

Brochuchus is an extinct genus of crocodile known from the Miocene Hiwegi Formation of Rusinga Island in Lake Victoria, Kenya. It contains a single species, Brochuchus pigotti. Brochuchus belongs to the subfamily Crocodylinae, which includes all living crocodiles. The closest living relative of Brochuchus is Osteolaemus, the dwarf crocodile. Compared to Osteolaemus, which has a small body and blunt snout, Brochuchus has a more generalized crocodylid anatomy. Brochuchus is characterized by a flat and relatively narrow skull, and although it is larger than Osteolaemus it is smaller than most other crocodylids. It has two prominent bumps on the surface of its snout.^[1]

The genus was named in honor of Christopher A. Brochu, for his scientific work on Crocodylia and its relatives. The unusual combination and spelling are intended as an auditory and visual pun such that the ‘ch’ sound in Brochu takes the place of the ‘s’ sound in ‘suchus.’ combined with ‘souchus’ (Greek for crocodile), which is a common suffix for crocodylomorph genera.^[1]

Phylogeny

A phylogenetic analysis published in 2013 found that Brochuchus was a close relative of Osteolaemus. Brochuchus and Osteolaemus are part of a clade within Crocodylidae informally called "osteolaemins". They are closely related to the genus Crocodylus, which includes most living crocodiles. Osteolaemins are among the most diverse groups within Crocodylidae, including the small-bodied and short-snouted Osteolaemus, the generalized and longer-snouted Brochuchus, the moderate-sized and horned Voay, and the very large-bodied Rimasuchus. Within osteolaemins, Brochuchus is most closely related to KNM-LT 24081, an unnamed species from Lothagam in Tanzania, and to Rimasuchus. Until recently another crocodylid from the Miocene and Pliocene of Africa called Euthecodon was thought to be closely related to Osteolaemus, Voay, and Rimasuchus, and together they were grouped in a clade called Osteolaeminae. Recent phylogenetic analyses, including the 2013 analysis with Brochuchus, place Euthecodon as a closer relative of the living Mecistops or slender-snouted crocodile. Together these two genera belong to a clade informally called "mecistopins" and are more closely related to the Crocodylus clade than are osteolaemins.^[1]

Paleobiology

Brochuchus has a generalized crocodylid body form with a long, narrow snout and a robust skeleton. Like most other species within Crocodylidae, Brochuchus was probably predatory and likely spent much of its time in water. As shown by the many mammal fossils that have been found on Rusinga Island, Brochuchus lived alongside several species of proboscideans (elephant relatives) and primates, the most famous of which is the early ape Proconsul. Although there is no direct evidence for what Brochuchus ate, it may have preyed on Proconsul. If this is the case, Brochuchus may have been one of the earliest anthropoidophagous ("ape-eating") crocodilians.^[1]

References