Mourasuchus amazonensis

Overview

Mourasuchus amazonensis is a member of the caiman lineage characterized by a long, broad, vertically flattened snout. A nearly complete skull and associated left lower jaw are known. Its unusual head rewards separate consideration of length, width, and height.^[1]

Key facts

The elongated snout is broad from side to side and flattened from top to bottom. The same head reveals different features depending on the viewing direction.^[1]

Time and place

The literature reports a Late Miocene occurrence. The broad summary of recorded fossil-bearing strata spans approximately 12–2.6 million years ago, from the Miocene into the Pliocene. Species-level cranial material can be explored alongside stratigraphic records.^[1][2]

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

Size, form and skeleton

The holotype is described as a nearly complete skull with an associated left lower jaw. Its long, broad snout is vertically flattened. Separate cheekbone material also appears in comparisons of the species.^[1]

Mourasuchus amazonensis was a crocodylian with a broad, long snout that lived in South American wetlands during the Miocene. A 2022 study compared the width of the type specimen’s skull with living adult crocodylians and accounted for relationships, estimating a body length of approximately 5.3 m. Even for the same fossil, size reconstructions vary with the bones and comparison methods used.^[3]

Habitat and reproduction

How does a flattened head look different from above and below? Snout width, jaw connections, and the arrangement of the palate can be examined separately. This animal invites its broad outline to be read from several directions.^[1]

Fossil discovery

In a 2019 reassessment, researchers directly examined the underside of the holotype and compared its upper surface with Price’s earlier illustrations. Reading old drawings alongside the surviving fossil provided new understanding of cranial structure.^[1]

References

1. Cidade et al. (2019) — Osteological reassessment of Mourasuchus amazonensis
2. Paleobiology Database — Age of fossil-bearing strata of Mourasuchus
3. Paiva et al. (2022) — Body-size estimates for Miocene South American caimanines
4. Ginsburg·Buffetaut (1978) — Evolution of the genus Euthecodon

Research questions

What information is added by viewing another side of the same specimen? The snout outline and lower-jaw connections can be compared together. Mourasuchus invites a view of the head from several sides, beyond its large silhouette in one direction.^[1]

Observation

Imagine the long, broad snout from above, then examine its low height from the side. Considering its connection with the lower jaw allows different views of the same head to be compared.^[1]