Mollusks from late Mesozoic seep deposits, chiefly in California
Kaim, Andrzej
Jenkins, Robert G.
Tanabe, Kazushige
Kiel, Steffen
Zootaxa
2014
3861
5
401
440
[238,420,712,738]
Gastropoda
Melanodrymiidae
Abyssomelania
Animalia
13
414
Mollusca
genus
gen. nov.
Typespecies. Abyssomelania cramptoni sp. nov.; Campanian (Late Cretaceous), from seep limestones found at Waipiro Bay, North Island, New Zealand(see Kiel et al.2013).
Diagnosis.Large, high-spired shell with abyssochrysoid early teleoconch whorls (reticulate with dominant axial ribs) and adolescent/adult whorls smooth apart from opisthocline growth lines and unusual widely-spaced prosocline riblets (named here abyssomelanid riblets) manifested only on abapical portion of the flank. Species included: The typespecies and A. campbellae sp. nov.
Remarks. Abyssomelaniais most similar to Ascheria gen. nov.described below but it differs by having the greatest whorl width at the adapical suture and lacking a subsutural constriction. Abyssochrysos Tomlin, 1927is usually smaller and more slender and has axial ribs present throughout the ontogeny. HumtulipsiaKiel, 2008 differs by having a deep notch near the basal margin. None of these genera possess the prosocline abyssomelanid riblets.
Etymology. Abysso- referring to deep water occurrences and – melaniato express the gross melaniform shell shape. Stratigraphic range.Albian (Early Cretaceous) to Campanian (Late Cretaceous).