Endoceras proteiforme

Overview

Endoceras proteiforme is an ancient cephalopod with a long, straight shell. The life reconstruction shows the smooth exterior of its shell. Fossil specimens also provide clues for studying the chambers and tube structures inside.^[1]

Key facts

The tube connecting the shell’s interior lies closer to the ventral wall than to the center. Its position and internal structures, as well as outward appearance, help identify the animal.^[1]

Time and place

Jillson’s 1931 Kentucky paleontological plate descriptions present this species as an Ordovician fossil. They include specimen 2081 from the Jessamine Formation in present-day Kentucky, United States.^[2]

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

Size, form and skeleton

The museum presents specimen MCZ128593 with a reported length of 12.2 cm. Its shell is straight and externally smooth; the account describes changes in cross-section and internal tube segments with growth stage.^[1]

Habitat and reproduction

The museum presents this species as an actively swimming cephalopod and explains that its shell could have drifted after death. This encourages consideration of movement during life and movement before fossil preservation.^[1]

Fossil discovery

The 1931 Kentucky plates record specimen 2081 as coming from the upper Jessamine Formation southwest of Spears. An old specimen number and plate description preserve the connection to its source.^[2]

References

1. Endoceras proteiforme — Cephalopoda
2. University of Kentucky archival material — Ordovician fossil plate descriptions from 1931
3. Atlas of Ordovician Life — Surface features and interpretations of the lifestyle of Rafinesquina
4. Harvard Museum of Comparative Zoology — Endoceras specimens and shell structure
5. University of Kentucky archival material — Ordovician fossil plate descriptions from 1931

Research questions

The museum’s species account is based on Flower’s 1955 study. It addresses the internal tube and the endocones within it, revealing features invisible from the exterior alone.^[1]

Observation

Inferred life reconstruction. Follow the smooth outer outline of the straight shell. Soft tissues, including the tentacles, eyes and funnel, as well as colour and pose are inferred. This is neither a cutaway of internal structures nor a calibrated illustration.^[1]