Purpurocardia Maxwell, 1969

Pérez, Damián E. & Del Río, Claudia J., 2017, Systematics of the family Carditidae (Bivalvia: Archiheterodonta) in the Cenozoic of Argentina, Zootaxa 4338 (1), pp. 51-84 : 72

Genus Purpurocardia Maxwell, 1969

Type species. Cardita purpurata Deshayes, 1854 (pl. 17, figs. 12–13) (by original designation). Pliocene–Recent of New Zealand, Recent of Australia.

Diagnosis. Carditid with small to medium-sized shell (between 30 and 60 mm in length), subcircular to subrectangular outline and posterior margin slightly truncated. Lunule small and prominent. Right valve hinge with a sinuous ventral edge. Right anterior tooth triangular; middle prominent, triangular, wide and ventrally concave; posterior tooth narrow and almost straight. Left anterior tooth short and triangular; posterior tooth elongate, narrow and slightly curved. External sculpture of 21 to 28 tripartite radial ribs, moderately wide with subelliptic transverse section, poorly developed paracostal ribs, intercostal spaces narrower than ribs (modified from Maxwell 1969: 174).

Included species. P. beata ( Marwick, 1928) (upper Miocene?–lower Pliocene, New Zealand), P. elegantoides ( Ortmann, 1899) (Eocene, Argentina and Chile), P. haskelli ( Fleming, 1950) (lower Pliocene, New Zealand), P. leonensis del Río, 1986 (upper Miocene, Argentina), P. lilliei ( Fleming, 1943) (lower–upper? Pliocene, New Zealand), P. penerectangularis ( Bartrum & Powell, 1928) (lower Miocene, New Zealand), P. perscrupulosa ( Marwick, 1932) (lower–middle Miocene, New Zealand), P. reigna ( Powell, 1933) (Recent, New Zealand), P. southlandica ( Fleming, 1955) (upper Miocene, New Zealand), P. titirangiensis ( Marwick, 1943) (upper Pliocene– Pleistocene, New Zealand), P. urutiensis ( Marwick, 1926) (upper Miocene, New Zealand), P. waikohuensis ( Marwick, 1926) (upper Miocene, New Zealand).

Remarks. According to Maxwell (1969), the main characters of Purpurocardia are a subcircular or subrectangular shell, smaller than 40 mm, sculptured with 21 to 28 tripartite and wide radial ribs with subelliptic transverse section and poorly developed paracostal ribs. This author restricted the genus to the lower Miocene– Recent interval of New Zealand and Recent of Australia, but del Río (1986) mentioned it for the late Miocene of Argentina, a record that subsequently wen unnoticed ( Beu & Maxwell1990; Beu 2006). We include here in Purpurocardia the species P. elegantoides ( Ortmann, 1899) from Eocene rocks of Santa Cruz and Chile, the oldest record of the genus.

Reichler (2010) mentioned Purpurocardia sp. from the Saladar Member of the Gran Bajo del Gualicho Formation (lower–middle Miocene, Río Negro Province) based on two valves. These specimens have subquadrate outlines, strong teeth and 21 entire radial ribs and we can assign it to young specimens of the planicostate Neovenericor austroplata ( Gardner & Bowles, 1939) ( Pérez et al. 2017a).