TY - JOUR

T1 - The origin of the Pycnodonteinae and relationship between gryphaeas and true pycnodontes

AU - Kosenko, Igor N.

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Berriasian (Early Cretaceous) oyster Pycnogryphaea weberae from Crimea is one of the earliest known pycnodonteine oysters. Examination of shell morphology and microstructure of this species shows that it shares characters of the subfamilies Gryphaeinae and Pycnodonteinae. Shell microstructure of Pycnogryphaea weberae lacks vesicular structure and is similar to microstructure of the genus Gryphaea. At the same time the shell of this species possesses morphological characters typical of pycnodonteins: development of chomata and well-defined circumferential curb. Pycnogryphaea weberae is regarded as a transitional taxon between the subfamilies Gryphaeinae and Pycnodonteinae and referred herein to a new genus Pycnogryphaea within the Pycnodonteinae. This suggests that the subfamily Pycnodonteinae likely originated from the Late Jurassic representatives of the genus Gryphaea (Gryphaeinae) in Berriassian. First pycnodonteins preserved shell microstructure of the genus Gryphaea but developed chomata along all the perimeter of both valves.

AB - Berriasian (Early Cretaceous) oyster Pycnogryphaea weberae from Crimea is one of the earliest known pycnodonteine oysters. Examination of shell morphology and microstructure of this species shows that it shares characters of the subfamilies Gryphaeinae and Pycnodonteinae. Shell microstructure of Pycnogryphaea weberae lacks vesicular structure and is similar to microstructure of the genus Gryphaea. At the same time the shell of this species possesses morphological characters typical of pycnodonteins: development of chomata and well-defined circumferential curb. Pycnogryphaea weberae is regarded as a transitional taxon between the subfamilies Gryphaeinae and Pycnodonteinae and referred herein to a new genus Pycnogryphaea within the Pycnodonteinae. This suggests that the subfamily Pycnodonteinae likely originated from the Late Jurassic representatives of the genus Gryphaea (Gryphaeinae) in Berriassian. First pycnodonteins preserved shell microstructure of the genus Gryphaea but developed chomata along all the perimeter of both valves.

KW - Berriasian

KW - Bivalvia

KW - Cretaceous

KW - Crimea

KW - Gryphaeinae

KW - Pycnodonteinae

UR - http://www.scopus.com/inward/record.url?scp=85058680090&partnerID=8YFLogxK

U2 - 10.4202/app.00494.2018

DO - 10.4202/app.00494.2018

M3 - Article

AN - SCOPUS:85058680090

VL - 63

SP - 769

EP - 778

JO - Acta Palaeontologica Polonica

JF - Acta Palaeontologica Polonica

SN - 0567-7920

IS - 4

ER -