Eurysternum wagleri

Overview

Eurysternum wagleri is a Late Jurassic turtle with a striking pentagonal carapace. The shell is widest slightly behind its midpoint and narrows sharply toward the rear. If you first picture a round turtle shell, discovering this different outline is rewarding.^[1]

Key facts

A deep notch is described at the center of the rear edge of the carapace. There is also a notch at the front center. These features help in reading the overall outline by following the shell’s margins.^[1]

Time and place

Late Jurassic specimens from Denkendorf–Zandt and Solnhofen in present-day Germany have been studied. The entire Jurassic spanned approximately 200–140 million years ago. A 2014 reassessment compared old turtle specimens from this region again.^[1][2]

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

Size, form and skeleton

The pentagonal carapace is narrower than it is long and tapers rapidly toward the rear. Central notches at the front and back are also characteristic. Several specimens preserve head, neck, and limb bones as well as the carapace, allowing different regions to be compared.^[1]

Habitat and reproduction

A turtle’s body is more than its carapace. Research on this species includes forelimbs, hind limbs, and tail vertebrae as well as the head and neck. It is rewarding to explore the rigid shell alongside the body extending beyond it.^[1]

Fossil discovery

A 2014 study reassigned specimens named Acichelys redenbacheri to this species. MNB R 2440.1 and .2 are two pieces of one specimen, while .3 is a plaster cast. This is an intriguing case in which three numbers do not represent three turtles.^[1]

References

1. A reassessment of the Late Jurassic turtle Eurysternum wagleri
2. International Commission on Stratigraphy (2024) — Geological time chart
3. Ebert (2026) — Reassessment of Mesturus and related fishes
4. Anquetin·Joyce (2014) — Reassessment of Eurysternum

Research questions

How do one slab of a fossil, its counterpart impression, and a plaster cast differ in what they reveal? Even material derived from one specimen helps explain different aspects. Reuniting old collection items offers new readings of a turtle’s name and form.^[1]

Observation

Follow the carapace outline from its broad region toward the narrowing rear tip. Finding the central notches at the front and rear in turn makes this turtle’s pentagonal outline clearer.^[1]