''Alcidellus'' is an oxyconic (sharp ventered)
haploceratacean ammonite
Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...
from the Middle Jurassic.
''Alcidellus'' was named as a genus buy Gerd Westermann in 1958. It is now generally seen as a subgenus of ''
Oxycerites'', differing from ''Oxyceratites (O)'' in having a broader venter with ventrolateral shoulders. The shell of ''Oxycerites'', including ''O (Alcidellus)'' is generally smooth, essentially involute with a small umbilicus, highly compressed with flanks converging on a narrow, somewhat sharp venter. Sutures are ammonitic.
''References''
;Notes
;Publications
* An Early Bathonian Tethyan Ammonite Fauna from Argentina, by Alberto C Riccardi and Gerd E.G. Westermann. Palaeontology, Volume 42. no2, pub online 21 Nov 2003
* Upper Bathonian and lower Callovian ammonites from Chacay Melehue (Argentina), by Horacio Parent. Acta Palaeontologica Polonica 43, 1, 69–130. 1998
{{Taxonbar, from=Q4713088
Middle Jurassic ammonites