Archaemacruroides ornatus
Archaemacruroides ornatus
Summary
Archaemacruroides ornatus was an early gadiform known from isolated sagittal otoliths. Modern work continues to recognise it as a very plesiomorphic gadiform, while the familial position of Archaemacruroides remains unresolved. The genus is therefore best treated conservatively within Gadiformes rather than forced into a living family.
Because the species is otolith-based, external body form and total body length cannot be reconstructed securely. Identification depends on preservation of the complete otolith outline together with the characteristic gadiform sulcus pattern; small, juvenile or eroded fragments should be left at a broader taxonomic level.
Quick Identification
Look for: a small, elongate gadiform otolith with a relatively flat inner face and a homosulcoid sulcus in which the cauda is only slightly longer than the ostium; species-level identification requires the complete outline and preserved sulcus.
Diagnostic Features
- Otolith is elongate and comparatively small, with a generalized early-gadiform outline.
- Inner face is relatively flat rather than strongly inflated.
- Sulcus is homosulcoid, with the cauda only slightly longer than the ostium.
- Collum is long and the anterior and posterior ends of the colliculi are reduced.
- Identification requires the combined outline and sulcus architecture; worn or juvenile fragments are not species-diagnostic.
Fossil Details
Recorded Fossil Sites
Reculver Sand Member
References
- Schwarzhans, W.W.; Mörs, T. (2021). Fish otoliths from the middle Paleocene (Selandian) of southern Sweden. GFF, 143(2–3), 277–282 View reference
- Stinton, F.C. (1965). Teleost otoliths from the Lower London Tertiaries. Senckenbergiana Lethaea, 46a, 389–425 View reference
- Ward, D.J. (1978). The Lower London Tertiary (Palaeocene) succession of Herne Bay, Kent. Report of the Institute of Geological Sciences. Institute of Geological Sciences View reference