''Kuttanacaiman'' is a monotypic genus of extinct caiman represented by the type species ''Kuttanacaiman iquitosensis''. ''Kuttanacaiman'' lived in what is now the

Amazon basin The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries of Bolivi ...

during the

Middle Miocene The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene. The sub-epoch lasted from 15.97 ± 0.05 Ma to 11.608 ± 0.005 Ma (million y ...

, approximately 13 million years ago (Ma). The species was named in 2015 on the basis of one nearly complete skull and a second partial skull from the Pebas Formation near

Iquitos Iquitos (; ) is the capital city of Peru's Maynas Province and Loreto Region. It is the largest metropolis in the Peruvian Amazon, east of the Andes, as well as the ninth-most populous city of Peru. Iquitos is the largest city in the world th ...

, Peru. ''K. iquitosensis'' is characterized by a short, rounded snout and blunt teeth at the back of its jaws that were likely adapted to crushing freshwater

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...

s. Its estimated total body length is . Kuttanacaiman size

Etymology

The genus name comes from the Quechua word ''kuttana'', meaning "grinding or crushing machine", and its species name honors the

native peoples.

Habitat

''Kuttanacaiman'' lived in Amazonia at a time before the Amazon River Basin was established; in its place was a massive wetland, called the

Pebas Mega-Wetland System Pebas District is one of four districts of the province Mariscal Ramón Castilla in Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the St ...

, that covered an approximate area of over in a drainage basin east of the still forming Andes, which at the time were experiencing rapid

uplift Uplift may refer to: Science * Geologic uplift, a geological process ** Tectonic uplift, a geological process * Stellar uplift, the theoretical prospect of moving a stellar mass * Uplift mountains * Llano Uplift * Nemaha Uplift Business * Uplif ...

in certain parts. ''Kuttanacaiman'' coexisted with six other crocodylian species, including two other caiman species with crushing dentitions: '' Gnatusuchus pebasensis'' and ''

Caiman wannlangstoni ''Caiman wannlangstoni'' is an extinct species of caiman that lived in what is now the Amazon Basin and surrounding areas during the Middle and Late Miocene. Fossils of ''C. wannlangstoni'' have been found in the Pebas Formation near Iquitos ...

''. Shells belonging to the bivalve genus '' Pachydon'' form thick fossil beds in the Pebas Formation and may have been a food source for ''Kuttanacaiman'' and these other caimans in swamps and marshes.

Taxonomy

A phylogenetic analysis published in 2015 indicates that ''Kuttanacaiman'' is one of the most

basal Basal or basilar is a term meaning ''base'', ''bottom'', or ''minimum''. Science * Basal (anatomy), an anatomical term of location for features associated with the base of an organism or structure * Basal (medicine), a minimal level that is nec ...

members of the

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

Caimaninae. Other basal caimanines such as ''Gnatusuchus'' and '' Globidentosuchus'' also possess crushing teeth, suggesting that this type of dentition was ancestral for the clade. Later caimanines, including most living species in the genus '' Caiman'', have more generalized dentitions, but some species such as ''C. wannlangstoni'' and '' C. latirostris'' seem to have re-evolved crushing dentitions. Below is a cladogram showing this evolutionary pattern, with crushing-dentition caimanine species in bold:

References

{{Taxonbar, from=Q20071778 Miocene crocodylomorphs Miocene reptiles of South America Mayoan Laventan Colloncuran Friasian Neogene Peru Fossils of Peru Fossil taxa described in 2015 Prehistoric pseudosuchian genera