Gryposuchus jessei

Overview

Gryposuchus jessei is a fossil crocodilian-line animal known from material at the front end of its long snout. Lateral expansion at the front and an undulating margin along the tooth sockets are described. Even this small anterior region of the head reveals several features.^[1]

Key facts

The snout tip of the holotype and the partial premaxilla and maxilla of UFAC1272 belong to different individuals. The same region survives in several fossils, allowing their shapes to be compared.^[1]

Time and place

The original 1912 description concerns material from sedimentary beds in the upper Amazon region. The recorded fossil-bearing strata are summarized as Miocene material dating to roughly 12–5.3 million years ago. The shape of the snout can be examined together with the record of its occurrence.^[2][3]

The time range describes source context, not the complete duration of this species.

Size, form and skeleton

The front end of the long snout expands to either side. Undulations are described along the margin where the teeth are located. The expansion of the overall outline can be compared separately from the arrangement of the smaller tooth sockets.^[1]

The portion of snout preserved in specimen UFAC1272 is about 24 cm long. This is distinct from the length of the entire head or body.^[1]

Habitat and reproduction

What differences can be recognized from the tip of a snout alone? Its lateral expansion and the undulations of the alveolar margin can be examined. In this animal, a small section of a long head becomes the starting point for taxonomic research.^[1]

Fossil discovery

Following the original description in 1912, Gryposuchus jessei was reassessed in 2018. The study described the snouts of the holotype and the separate specimen UFAC1272 and addressed comparisons within the genus. It is an example of reading new fossils alongside an old name.^[1][2]

References

1. Rafael Gomes de Souza, Douglas Riff, Jonas P. de Souza-Filho, Alexander W. A. Kellner (2018). Revisiting Gryposuchus jessei Gürich, 1912 (Crocodylia: Gavialoidea): specimen description and comments on the genus. Zootaxa 4457(1):167–178.
2. Gürich (1912) — Original description of Gryposuchus from the upper Amazon
3. Paleobiology Database — Age of fossil-bearing strata of Gryposuchus
4. Ginsburg·Buffetaut (1978) — Evolution of the genus Euthecodon

Research questions

What shared features do the anterior head regions assigned to the same species reveal? The margins and tooth sockets of the overlapping known portions can be compared. This research reads the same region in different specimens side by side.^[1]

Observation

Move your gaze from the lateral expansion at the snout tip to the alveolar margin. Examining both the broad widening and the small undulations reveals several features of the front of the head.^[1]