Organism · Placental mammals
Toxodon platensis
Source time context (not species duration) · ≈ 2.58–0.0117 Ma
Inferred life reconstruction
Toxodon platensis
Overview
Toxodon platensis is an extinct South American mammal with a long, low skull and robust cheek regions. It is also known through comparisons within Toxodon, a group with large bodies and short necks. The head and teeth offer a starting point for exploring this ancient mammal's body.[1][2][3]
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Key facts
Its upper incisors were not all the same size. The original description in 1837 discussed differently sized incisors and broad, robust cheek regions. Even a body resembling a familiar large animal can reveal distinctive features in small dental differences.[1]
Time and place
It is known from Pleistocene South America. Museum accounts focus on the Late Pleistocene. The Pleistocene spans roughly 2.6 million to 12,000 years ago.[3][5]
The time range describes source context, not the complete duration of this species.
Size, form and skeleton
The species' skull is long and low, with broad, robust cheek regions. Comparative anatomy of the genus Toxodon describes a thick trunk, short neck, hindlimbs longer than the forelimbs, and short, broad feet. Examine the differing proportions of the head and trunk together.[1][2]
A 2023 body-mass study estimated this species at about 1–1.2 tonnes. This range was inferred from measurements of fossil bones.[13]
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Habitat and reproduction
Large incisors and robust jaws provide clues for studying food-processing structures. The weight-bearing limbs and broad feet are compared as well. Examining the head, teeth and large body together helps researchers explore the lives of South American mammals.[1][2]
Fossil discovery
Owen described the skull and teeth of Toxodon platensis in 1837. Subsequent comparative anatomical research added information about the trunk and limbs, and two separate skulls were studied in 2021. Different specimens and periods of research reveal different parts of the body.[1][2][4]
References
- Owen (1837) — First description of Toxodon platensis
- Liendo Lazarte (1941) — Comparative anatomy of Toxodon
- Natural History Museum — The story of Toxodon
- Barros Silva & Oliva (2021) — A study of the skull of Toxodon
- International Commission on Stratigraphy (2024) — Geological time chart
- Lopes et al. (2021) — Ice Age fossil mammals of the Chuí River
- Natural History Museum — The story of Toxodon
- International Commission on Stratigraphy (2024) — Geological time chart
- Owen (1837) — First description of Toxodon platensis
- Liendo Lazarte (1941) — Comparative anatomy of Toxodon
- Vizcaíno et al.2011 — Limb proportions and function in glyptodonts
- Blanco et al.2009 — The center of percussion of biological hammers
- 2023 study — Estimating body mass in South American native ungulates
Research questions
Are large mammals with similar external appearances close relatives? Their teeth, skulls and limb configurations are compared together. Toxodon's unfamiliar combination raises questions about the relationships and lives of mammals that evolved in South America.[1][2][3]
Observation
Move your gaze from the long, low head to the broad cheek regions, short neck and thick trunk. Look also at the differences between forelimbs and hindlimbs and at the short, broad feet.[1][2]
Related organisms
Mylodon darwiniPlacental mammalsSource time context (not species duration) · ≈ 2.58–0.0117 MaDifferent large mammals of the Chuí Creek fossil assemblage
Mylodon and Toxodon both appear in research on the Ice Age fossil assemblage of Chuí Creek. Large mammals with different bodies can be compared within the fossil record of the same area.
Doedicurus clavicaudatusPlacental mammalsSource time context (not species duration) · ≈ 2.58–0.0117 MaHeads and armour in Pleistocene South America
Examine Toxodon's long, low skull alongside Doedicurus's armoured body. Compare different mammalian bodies within the broad temporal and regional setting of Pleistocene South America.