Coccosteus cuspidatus

Overview

Coccosteus cuspidatus is a Devonian fish known for armor covering its head and front trunk and for its jaw plates. A joint connects the hard head and trunk. We can examine the arrangement extending from armor to fins and tail.^[2][1]

Key facts

A single dorsal fin with a long base and a tail with unequal upper and lower portions are described on the rear part of the body. The front armor can be read separately from the different rear outline.^[1]

Time and place

It is known from Middle Devonian material at Edderton and in the Old Red Sandstone of present-day Scotland. The Devonian as a whole spanned approximately 420–360 million years ago. Museum records and geological conservation accounts convey its locality and age.^[2][3][4]

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

Size, form and skeleton

Hard armor covers the head and front trunk, with a joint between them. Tooth plates are described in the jaws. The rear body is studied as an arrangement continuing into a long-based dorsal fin and an asymmetrical tail.^[2][1]

The species account in a geological conservation description gives a length of approximately 40 cm.^[2]

Habitat and reproduction

Where are the connections in the body of an armored fish? A joint between the head and front trunk is described in Coccosteus. Examining connections between hard plates helps reveal the broad body arrangement.^[2]

Fossil discovery

Accounts of Scottish Devonian fossil fishes describe the armor and jaw structures. A 2024 comparative reconstruction study also discussed the fins and tail of Coccosteus. Questions extend from the hard front body to the rear outline.^[2][1]

References

1. Engelman (2024) — Comparing body reconstructions of Coccosteus
2. GCR16 Chapter6: Mid Devonian fossil fishes sites of Scotland
3. Natural History Museum, London — Coccosteus specimen record
4. International Commission on Stratigraphy (2024) — Geological time chart
5. Trewin (2003) — The story of an armoured fish that looked winged
6. Photograph caption in a collected volume — Middle Devonian Pterichthyodes
7. Dineley (1999) — Fossil fishes from the Middle Devonian of Scotland
8. Natural History Museum, London — Coccosteus specimen record
9. International Commission on Stratigraphy (2024) — Geological time chart
10. Engelman (2024) — Comparing body reconstructions of Coccosteus
11. Achanarras Quarry SSSI — Site Management Statement

Research questions

What evidence should be compared when reconstructing a fish’s tail? The study cautioned against interpretations that extend the rear body and tail of Coccosteus too far. It asks how known connections can inform the proportions of the whole animal.^[1]

Observation

First examine the joint between the armor of the head and front trunk. Then move your gaze to the dorsal fin and asymmetrical tail of the rear body to see how its arrangement differs from the hard front region.^[2][1]