Figure 2
From: Mass occurrence of seep-specific bivalves in the oldest-known cold seep metazoan community
The modiomorphid bivalve Ataviaconcha sp. from El Borj. (a) Left-lateral view of a left valve, with partially preserved anterior lobe. (b) Left-lateral view of a partially preserved left valve showing well developed posterior lobe (arrow); note strong carina extending from the anterior towards the posterior lobe (asterisk). (c) Left-lateral view of a partially preserved internal mould of a left valve; note an enlarged and fan-shaped posterior lobe (arrow) and carina extending from the anterior towards the posterior lobe (asterisk). (d) Field view of a large, incurved Ataviaconcha specimen (outline shown in the inset). The few visible specimens of the brachiopod Septatrypa lantenoisi are indicated with arrows. (e,f,) Field view (e) and corresponding schematic drawing (f) of the bivalve-brachiopod assemblage (black – bivalves; white – brachiopods). Note the common deformations of the bivalve shells due to their diagenetic recrystallisation and partial dissolution. Coin (e); 21 mm in diameter) for scale. (g) Thin-section view (cross-polarised light) of two bivalve shells (B). Note recrystallisation of the original shell material to a sparry calcite mosaic, with preservations of some remnants of the original multi-layered structure. The shell was partially corroded and coated with clotted micritic carbonate (arrow).
