Varanus prisca

Overview

Varanus prisca is a member of the monitor-lizard group known from Australian fossils. Humeri assigned to this species provide clues to robust limbs. Research comparing ancient lizards continues through this single body region.^[1]

Key facts

One humerus examined in a 2005 study was interpreted as belonging to an individual still growing. This considered developmental stage alongside bone shape. A single fossil can open questions about an animal’s growth.^[1]

Time and place

It is known from the Australian fossil record. Recorded occurrences are summarized as Pliocene and Pleistocene material. The broad combined background of these epochs is approximately 5.3 million–12,000 years ago.^[2][3]

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

Size, form and skeleton

The main clues are robust humeri assigned to this species. The upper arm is the part of the forelimb nearest the trunk. Detailed comparisons of a single limb bone help reveal the form of an ancient monitor lizard.^[1]

The Australian Museum’s account of Megalania describes a body length exceeding 5 m.^[4]

The same account gives a body mass of approximately 300 kg.^[4]

Habitat and reproduction

What clues can the bones of a growing animal provide about its body? Research on the humerus offered an interpretation of an immature individual alongside its morphology. The evidence encourages consideration of limb robustness and growth stage together.^[1]

Fossil discovery

Reed and Hutchinson’s 2005 study described humeri of fossil monitor lizards. SAMP 40102 from Naracoorte is treated as material from an immature individual assigned to this species. Records of individual bones lead to comparisons of species and growth.^[1]

References

1. Reed·Hutchinson (2005) — Study of a fossil monitor lizard humerus
2. Paleobiology Database — Age of occurrences of Varanus prisca
3. International Commission on Stratigraphy (2024) — Geological time chart
4. Australian Museum — Prehistoric Australia
5. Australian Museum — Prehistoric Australia
6. Paleobiology Database — Fossil occurrence records for Archaeovaranus lii
7. Dong et al. (2022), “A new stem-varanid lizard (Reptilia, Squamata) from the early Eocene of China,” Philosophical Transactions B 377:20210041.
8. Dong et al. (2022) — A new stem-varanid lizard from the early Eocene of China
9. IVPP — 中国巨蜥科化石新属种支持巨蜥科的亚洲起源说

Research questions

Do juvenile and adult bones have the same proportions? Comparing material from different growth stages changes the questions asked about form. The humerus of Varanus prisca invites consideration of growth context.^[1]

Observation

First examine where the upper arm lies in the forelimb. Holding the two clues of robust bone and growth stage in mind helps follow the questions of fossil lizard research.^[1]