Machimosaurus hugii

Overview

Machimosaurus hugii was a Jurassic crocodyliform studied through its snout, postcranial bones, and body armor. Material from Guimarota in present-day Portugal provides important clues. Pieces from the head, trunk, and tail tell its story.^[1][2]

Key facts

The Guimarota material includes reported trunk, sacral, and tail vertebrae and ribs as well as head fragments. A left fibula and armor material are also documented. Although its snout is striking, other parts of its body are worth exploring too.^[2]

Time and place

It is studied through material from the Alcobaça Formation at Guimarota, Leiria, in present-day Portugal. A reassessment of Late Jurassic Machimosaurus treated this material as belonging to the species. The Jurassic spanned approximately 200–140 million years ago.^[1][3]

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

Size, form and skeleton

Material assigned to the species includes fragments of the upper jaw in the snout and an incomplete braincase. The original description discusses an elongated snout formed by the upper jaw bones. Vertebrae, ribs, armor, and limb bones add clues about different parts of the body.^[1][2]

Machimosaurus hugii is estimated to have been approximately 6.9 m long. A 2016 study separately calculated the proportions of these animals, whose heads were large relative to their bodies, lowering earlier estimates of at least 9 m. This reconstruction may change until a complete skeleton is found.^[4]

Habitat and reproduction

Comparisons of crocodyliforms consider the snout, teeth, and body armor together. The diagnosis of the genus Machimosaurus includes a robust snout and blunt teeth. Reading the shared features of the genus alongside species-level specimens from Guimarota helps clarify the scope of each comparison.^[1][2]

Fossil discovery

A 1968 study reported head material and associated postcranial bones from Guimarota. A 2014 reassessment compared broadly grouped Machimosaurus material again at the species level. By examining differences within the genus, researchers read old discoveries in a new light.^[1][2]

References

1. 2014 study — Distinguishing species of Machimosaurus
2. 1968 study — Machimosaurus from Guimarota
3. International Commission on Stratigraphy (2024) — Geological time chart
4. Young et al. (2016) — Body proportions and revised size estimates of marine crocodylomorphs
5. de Souza et al. (2018) — Reassessment of Gryposuchus jessei

Research questions

Do fragments of the head and postcranial bones answer the same questions? The snout reveals the organization of the head, while vertebrae and armor inform us about other parts of the body. Combining information from each region helps compare the diversity of crocodyliforms.^[1][2]

Observation

Move your gaze from the elongated snout to the trunk, armor, and tail. Looking at several body regions in turn reveals different features from those seen in the head’s overall outline alone.^[2]