Barbierella Chavan 1938
Creators: name: Taylor, John D.
name: Glover, Emily A.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Bivalvia
Lucinoida
Lucinidae
Barbierella

description: Genus Barbierella Chavan, 1938
Cavilucina (Barbierella) Chavan, 1938: 115.
TYPE SPECIES. — Lucina barbieri Deshayes, 1857, early Eocene, Paris Basin (original designation).
DIAGNOSIS. — Small, less than 12 mm long, ovately trigonal, prominent posterior sulcus, with marginal sinus. Sculpture of prominent, reflexed, regularly spaced, scalloped, commarginal lamellae with underlying radial undulations. Thickening of lamellae aligned in radial lines. Lamellae raised into short spines along ventral edge of posterior sulcus. Lunule short, deeply impressed. Ligament short, external. Hinge: RV with a single narrow cardinal tooth, LV with a socket. Lateral teeth absent or vestigial, small anterior lateral tooth present in B. barbieri. Anterior adductor muscle scar short, diverging from pallial line for about 1/3 of length. Pallial line entire. Inner shell margin undulose to coarsely plicate.
GEOLOGICAL RANGE. — Paleocene (Late Danian) to Recent.
INCLUDED SPECIES. — Paleocene. Late Danian: Barbierella briarti (Cossmann, 1908) Calcaire de Mons, Belgium (see Glibert & van de Poel 1973: 28, pl. 5, fig. 5).
Eocene. Barbierella barbieri (Deshayes, 1857) (1857: 651-652, pl. 43, figs 1-5) known from Ypresian and Lutetian of the Paris Basin, France (Fig. 3 A-D); also figured by Cossmann & Pissarro (1904 -6, pl. 24, fig. 82-16). Barbierella navicula (Cossmann, 1904) (1904: 152, pl. 10, figs 18-20) is a similar species from Bartonian sands at Bois-Gouët, Loire-Atlantique, France.
Miocene. Barbierella miobarbieri (Sacco, 1901) (1901: 97, pl. 21, fig. 6), Piedmont, Italy (Fig. 3E, F), see also Merlino (2007: pl. 15, fig. 12a, b).
Recent. Barbierella louisensis (Viader, 1951) Mauritius and Mozambique Channel (Fig. 4) and synonym B. scitula Oliver & Abou-Zeid, 1986, northern Red Sea (Fig. 4 E-G).
REMARKS
The hinge of B. barbieri was illustrated by Cossmann (1913: 86, fig. 100) who claimed two cardinal teeth in each valve with the anterior much reduced. He also illustrated anterior and indistinct posterior lateral teeth in each valve but these are barely visible in Eocene specimens we have examined (Fig. 3B, C). In living B. louisensis the lateral teeth are absent and there are no visible cardinal teeth in the left valve but they may be fused with the edge of the lunule and ligamental ridge.
Prior to the introduction of the name Barbierella the placement of Lucina barbieri had been unstable and variously included in Phacoides Agassiz, 1846, Here Gabb, 1866 and Lucinisca Dall, 1901, although Cossmann (1913: 86) recognised its unusual features and uncertain assignment. Proposing Barbierella as a subgenus Chavan (1938: 114-115) considered it related to but separate from Cavilucina P. Fischer, 1887 and also noted a possible resemblance to Recurvella Chavan, 1937 (type species Lucina dolabra Conrad, 1833) from the Eocene of eastern United States of America (USA). Sacco (1901) placed B. miobarbieri in Here Gabb, 1866, Recent, northeastern Pacific, probably because of the deeply scooped lunule but otherwise the shells are dissimilar. Later, Woodring (1925: 121) stated “The lucinoid described by Sacco as Here miobarbieri from the Helvetian of the Piedmont basin, probably is a Pleurolucina ”. However, although there is some similarity of external sculpture the hinge teeth are quite different, Pleurolucina Dall, 1901 having two cardinal teeth and prominent lateral teeth in each valve. The deeply scooped lunule impinging on the cardinal teeth and commarginal lamellae resemble some living Lamellolucina Taylor & Glover, 2002 species such as L. gemma (Reeve, 1850) but all species in the genus have strong lateral teeth. Although from shell characters we place Barbierella in the Lucininae the relationships of this enigmatic genus remain uncertain pending inclusion in molecular analyses.
Throughout their geological range Barbierella species have always been rare. In the original description of B. barbieri Deshayes (1857: 652) remarked on “this rare and beautiful shell”. Sacco (1901: 97) said that B. miobarbieri (as Here) was rather rare in the Miocene of northern Italy. From probable mid-late Miocene rocks of Cyprus, Reed (1935: 5) recorded a partial external mold (SM C8911) of Barbierella miobarbieri (as Phacoides (Pleurolucina )) and Studencka et al. (1998) recorded B. miobarbieri as rare in mid-Miocene deposits of Parathethys.
description: Published as part of Taylor, John D. & Glover, Emily A., 2018, Hanging on - lucinid bivalve survivors from the Paleocene and Eocene in the western Indian Ocean (Bivalvia: Lucinidae), pp. 123-142 in Zoosystema 40 (7) on pages 129-130, DOI: 10.5252/zoosystema2018v40a7, http://zenodo.org/record/3738245