Prosqualodon australis

Overview

Prosqualodon australis is an extinct toothed whale known from Patagonian fossils. A 2025 reassessment presents it as an ancient short-snouted toothed whale. Research beginning with skulls and jaws extended to other bones.^[3]

Key facts

Ear bones also provide clues for studying whales. Material examined by True included ear bones alongside jaws and teeth. Moving from the outline of a large body to the shape of a small bone reveals another path for fossil comparison.^[1]

Time and place

The species is presented through the early Miocene fossil record of Patagonia. Skulls from the Gaiman Formation in present-day Chubut Province, Argentina, have been studied. Even within the broad Patagonian setting, it is useful to follow localities alongside formations.^[2][3]

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

Size, form and skeleton

A short snout and differently shaped teeth are notable features. An author abstract comparing skulls discusses varied tooth forms, crowns, and enamel features together. Alternate between the overall head outline and small dental differences.^[2][3]

Prosqualodon australis is an ancient toothed whale whose size can be compared across growth stages. A 2019 study estimated a juvenile specimen at approximately 2 m long and an adult at approximately 3 m. These are reconstructions of the two individuals studied, not the species’ maximum length.^[4]

Habitat and reproduction

Patagonian strata provided new material for understanding ancient toothed whales. A 2025 study examined newly collected skulls, ear bones, and postcranial bones from fieldwork in early Miocene layers. It combines several kinds of evidence rather than relying on one bone type.^[3]

Fossil discovery

On April 22, 1899, J. B. Hatcher collected material from Patagonian strata at San Julián. True’s 1909 study listed lower jaws and teeth, the first neck vertebra, dorsal vertebrae, and rib fragments, among other material. He compared these with an earlier description and assigned them to the same species.^[1]

References

1. True (1909) — Jaw and body bones of Prosqualodon collected at San Julián
2. Authors’ conference abstract — Skull and teeth of Prosqualodon from the Gaiman Formation
3. Gaetán et al. (2025) — Morphological and phylogenetic reassessment of Prosqualodon australis
4. Gaetán et al. (2019) — Reassessment of Early Miocene toothed whales from Patagonia
5. Reassessment study — Xiphiacetus, a long-snouted toothed whale

Research questions

Even fossils of the same species preserve different parts. An author abstract distinguishes the partial type skull MLP 5-8 from nearly complete skull MLP 5-9 for comparison. Finding in one specimen features absent from another broadens research.^[2]

Observation

First examine the short snout and lower-jaw outlines. In fossil material, find preserved tooth positions and jaw connections. Distinguish the overall head impression from small skeletal features to observe the ancient whale more closely.^[1][3]