Article: Malayomaorica gen. nov. (Family Aviculopectinidae) from the Indo-Pacific Upper Jurassic; with comments on related forms

Critical reinvestigation of the aviculopectinid form 'Aucella' malayomaorica Krumbeck from the late Jurassic of the Indo-Pacific region indicates that it does not belong either to the genus Buchia (= Aucella) or to any other known aviculopectinid genus. A new genus Malayomaorica is erected to receive 'Aucella' malayomaorica. This genus is characterized by: (1) presence of a submedian furrow-like excavation in the ligamental pit of the left valve; (2) presence of an irregularly shaped tooth-like bulge in front of the ligamental pit at the anterior margin of the left ligamental plate; (3) presence of a strong ligamental ridge rising above the true dorsal shell margin in the right ligamental plate; and (4) a wide to very wide byssus notch.Malayomaorica gen. nov. is much more closely allied to Meleagrinella, Aucellina, and Arctotis than to Buchia. This genus is, accordingly, placed in subfamily Oxytominae and not in Buchiinae (= Aucellinae). The genus Aucellina is also placed in the Oxytominae, as it appears to be an independent offshoot of Meleagrinella unrelated to Buchia.The boreal genus Arctotis is the closest known ally of Malayomaorica. The latter is accordingly interpreted as an offshoot of the Arctotis lineage, which immigrated, together with the true Buchia species, into the Indo-Pacific region during the early part of the Upper Jurassic.