Baru

Baru
Temporal range: Late Oligocene - Late Miocene,
28.1–8 Ma[1] [2]
Holotype skull of B. darrowi
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauromorpha
Clade: Archosauriformes
Order: Crocodilia
Clade: Mekosuchinae
Genus: Baru
Willis et al., 1990
Species
  • Baru darrowi Wilis et al., 1990 (type species)
  • Baru iylwenpeny Yates, Ristevski & Salisbury, 2023
  • Baru wickeni Willis, 1997

Baru, sometimes referred to as the cleaver-headed crocodile, is an extinct genus of Australian mekosuchine crocodilian. Its fossils have been found from various Late Oligocene and Miocene localities from across the Northern Territory and Queensland, indicating that Baru was a common genus during the late Paleogene and early Neogene. Three species are recognized, B. darrowi, B. iylwenpeny, and B. wickeni.

Baru was a large and powerful mekosuchine with an incredibly deep and robust skull and long teeth with compressed crowns that in the case of Baru darrowi are furthermore adorned with minute serrations. At a length of around 4 m (13 ft), it was among the largest crocodilians native to Australia at the time and the largest predator of its ecosystem. With dorsally oriented nostrils and eyes and a poor range of head movement, as well as its fossils being associated with freshwater environments, Baru is generally interpreted to have been a semi-aquatic ambush hunter, spending much of its day submerged in water waiting for prey.

While the skull of Baru broadly resembles that of modern crocodiles, its much more robust morphology suggests that it hunted somewhat differently. Willis and colleagues suggest that it inhabited shallower waters that were not suited to drown potential prey items as done by today's crocodiles. Instead, it may have relied on its powerful bite and compressed teeth to quickly incapacitate its prey, minimalizing the risk of it escaping during the ensuing struggle in the shallow waters. The bite of Baru is thought to have been powerful enough to take out even large mammals up to a weight of 300 kg (660 lb) and even other crocodilians, which were abundant in the environments Baru inhabited.

Although highly successful during the Oligocene and Miocene, Baru eventually fell victim to changes in Australia's climate at some point during the Late Miocene. One hypothesis suggests that the continent was hit by an especially devastating pulse of aridification that was severe enough to destroy the habitat preferred by Baru, before conditions improved again leading into the Pliocene. This may explain the drastic faunal turnover that occurred between the Miocene and Pliocene.

  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. ^ Cite error: The named reference YRS23 was invoked but never defined (see the help page).