Ikanogavialis

Ikanogavialis is an extinct genus of gryposuchine gavialoid crocodilian. Fossils have been found in the Urumaco Formation in Urumaco, Venezuela and the Solimões Formation of Brazil. The strata from which remains are found are late Miocene in age, rather than Pliocene as was once thought. A possible member of this genus survived into the Late Holocene on Muyua or Woodlark Island in Papua New Guinea.
Description.
"Ikanogavialis" had a dorsoventrally deep snout and a distinctive notch between the dentary and maxillary alveoli. The external nares projected anterodorsally from the rostrum. This can be seen as a plesiomorphic characteristic in crocodilians, but given that the earliest gavialoids possessed dorsally projecting external nares, this feature can be seen as having been a reversal from the gavialoid apomorphy back to the crocodilian plesiomorphy rather than having been directly obtained from an early crocodilian ancestor.
Species.
The type species of "Ikanogavialis" is "I. gameroi". It was named in 1970 from material found from the Urumaco formation. A Pleistocene gavialoid named "Gavialis papuensis" from Murua also known as Muyua or Woodlark Island, part of Papua New Guinea (erroneously considered part of the Solomon Islands in some sources), bears some vague similarities with "Ikanogavialis" and was referred to the genus in 1999, along with other slender-snouted forms from the Neogene of South America and Africa.
Paleobiology.
"Ikanogavialis" may have lived in a coastal paleoenvironment along with other gavialids such as "Gryposuchus". The strata of the Urumaco formation were deposited in both marine and fluvial settings, although it is unclear to which portion both genera belong. Other gavialoids such as "Siquisiquesuchus" and "Piscogavialis" are known to have lived in coastal environments, and it is likely that extant freshwater gavialoids such as "Gavialis" may have originated from these coastal forms. "Ikanogavialis" also existed with many other crocodilians in Venezuela during the late Miocene including the giant caiman "Purussaurus" and an extinct species of "Melanosuchus".
"Gavialis"/"Ikanogavialis papuensis" was similarly fully marine, having been found in association with sea turtles and sirenians. It represents the youngest fully marine crocodilian to date.