Amphorometra ornata
Amphorometra ornata
Summary
Amphorometra ornata was a feather star, a crinoid whose adult body was not permanently supported by a long stalk. Like living comatulids it would have spread feathery arms into the water to trap suspended organic particles and plankton, using cirri or other attachment structures to grip the substrate when resting or feeding.
Its lightly connected skeleton was particularly prone to disarticulation. London Clay occurrences are consequently expected to be dominated by small brachial, centrodorsal or cirral ossicles, so reconstructing the whole animal requires comparison with articulated comatulid anatomy.
Quick Identification
Look for: small, ornamented feather-star ossicles rather than stalk columnals, especially centrodorsal, cirral or arm elements; secure identification needs well-preserved articular surfaces and comparison with described comatulid material.
Diagnostic Features
- Adult skeleton lacks the long persistent stalk typical of isocrinid sea lilies.
- Centrodorsal and cirral ossicles are important for attachment and identification.
- Arm ossicles have paired articular surfaces adapted to flexible feather-star arms.
- Surface ornament and ossicle proportions provide the species-level characters implied by the name ornata.
- Loose, featureless crinoid ossicles should not be assigned to Amphorometra without diagnostic morphology.
Fossil Details
Recorded Fossil Sites
No fossil-site occurrences have yet been recorded for this species.
References
- Roux, M.; Martinez, A.; Vizcaïno, D. (2021). A diverse crinoid fauna (Echinodermata, Crinoidea) from the Lower Eocene of the Gulf of Languedoc (Corbières, Aude, southern France). Zootaxa, 4963(2), 201–242 View reference