Eotalpa anglica

Overview

Eotalpa anglica is an early mole known from Late Eocene Britain. Its tapering snout, primitive forelimbs, and foot bones have been studied. It raises questions about how moles acquired bodies suited to digging.^[1]

Key facts

Finding small fossils sometimes depends more on a fine sieve than a shovel. Isolated bones used in the study were collected by washing sediments through a 0.5 mm mesh. Small teeth and foot bones accumulated to tell the story of an ancient mole.^[1]

Time and place

This animal lived near the beginning of the Late Eocene, around 38 million years ago. The type locality is HH2 at Headon Hill on the Isle of Wight in present-day Britain. Upper and lower jaw material is also known from Hordle Cliff in the Hampshire Basin.^[1]

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

Size, form and skeleton

The front of the snout narrows, with a sloping lower anterior edge. A primitive ulna and bones of the forefeet and hind feet are compared together. Comparison with living moles helps explore changes in arms and hands specialized for burrowing.^[1]

Habitat and reproduction

The author interpreted the ankle bones as suited to terrestrial life. Claws, metapodials, and the ulna were considered to show early stages of burrowing adaptation. Several body regions thus inform research on life above ground and digging ability together.^[1]

Fossil discovery

The material used in the original 1977 description consisted of two upper molars. Later, jaws and small postcranial bones were added from washed and sieved sediments. Comparing the locality of the reference teeth with those of other bones helped reveal the body of an early mole.^[1]

References

1. Skeletal adaptations and phylogeny of the oldest mole Eotalpa (Talpidae, Lipotyphla, Mammalia) from the UK Eocene: the beginning of fossoriality in moles
2. Hooker2016 — The skeleton and burrowing adaptations of the early mole Eotalpa
3. Smith, De Wilde & Steurbaut (2004) · Primitive Equoid and Tapiroid mammals: keys for interpreting the Ypresian-Lutetian transition in Belgium · Bulletin RBINS Earth Sciences74 Supplement:165–175
4. Ring et al. 2020 — Divergent mammalian body size in a stable Eocene greenhouse climate
5. Luke T. Holbrook (2009) · Osteology of Lophiodon Cuvier,1822 (Mammalia,Perissodactyla) and its phylogenetic implications · JVP29(1):212–230 · DOI10.1671/039.029.0117

Research questions

Did a mole’s digging ability develop all at once? Comparing the ulna, ankle, and claws of early species helps investigate the sequence of adaptations. When postcranial bones are added to an animal known from small teeth, questions about lifestyle also expand.^[1]

Observation

Move your gaze from the narrow snout to the forelimbs and feet. In particular, imagine how bones within the elbow and ankle might relate to a digging lifestyle.^[1]