Alfaites romeo, Valent & Fatka & Marek, 2019

Valent, Martin, Fatka, Oldřich & Marek, Ladislav, 2019, Alfaites romeo gen. et sp. nov., a new Hyolitha from the Cambrian of Skryje-Týřovice Basin (Czech Republic), European Journal of Taxonomy 491, pp. 1-10 : 5-7

Alfaites romeo gen. et sp. nov.

urn:lsid:zoobank.org:act:2EA9355A-4894-4F7B-AFDA-1000BCE24C3C

Fig. 2

Etymology

The specific epithet ‘ romeo ’ refers to the Shakespeare’s protagonist Romeo Montague. Marek initially planned to describe two closely related taxa as A. romeo and A. julia . The only specimen designated as A. julia ( Fig. 2D ) in the original collection of L. Marek does not show any difference in morphology and should be classified as A. romeo .

Material examined

Holotype

CZECH REPUBLIC – Skryje-Týřovice Basin • Inner side of operculum; NM L46640 .

Paratypes

CZECH REPUBLIC – Skryje-Týřovice Basin • Inner side of operculum; NM L 46642 • External sides of operculum; NM L 46646, NM L46641 • Inner mould of conch; NM L 46645 • External moulds of conchs; NM L 46643, L46644 .

Referred material In addition to the holotype and paratypes, parts of another three conchs and five opercula (collection NM Ls 858), all deposited in collections of the National Museum (Prague, Czech Republic).

Type horizon Paradoxides (Eccaparadoxides) pusillus Zone, Skryje Member, Buchava Formation, Drumian , middle Cambrian, Barrandian area, Czech Republic.

Diagnosis

As for the genus.

Description

Monoclaviculate operculum with clavicles of bow-shaped transverse cross-section. The angle of divergence of clavicles reaches 135° on the type specimen (NM L46640). Open margins of clavicles overlap above the inner surface operculum (interclavicular concavity). Distal ends of clavicles cut off. Cardinal processes broadly divergent with rounded distal ends, mutually separated by a narrow and shallow groove in linear axis of operculum. Bases of cardinal processes diverging at an angle of 90° toward the dorsal margin of operculum. Uncommon and relatively robust cardinal teeth are developed along the dorsal margin. Cardinal shield is concave in centre and slightly vaulted at the sides. Rooflets clearly distinct and bordered by grooves. Sculpture of operculum consists of growth-lines and fine radial ribs, more distinct near anterior margin of conical shield. Area of operculum adjacent to summit of operculum is nearly smooth. Width and length of inner side operculum is 8.8 mm and 5.5 mm for holotype NM L44640 , 7.7 mm and 4.7 mm for paratype NM L44642 ; width and length of outer side of operculum is 7.6 mm and 4.9 mm for paratype NM L44641 and 6.7 mm and 4.7 mm for paratype NM L44646 . Length of the conical shield is 4.0 mm for paratype NM L44641 and 3.7 mm for paratype NM L44646 .

Conch with subtriangular cross-section. Ventral side very slightly vaulted to almost flat; lateral edges sharply rounded; dorsal side strongly rounded. Amblygonal aperture with dorsal margins vaulted slightly forwardly. The w/h index of conch at aperture is 2.2 (width of aperture of specimen NM L46645 is 7.1 mm and height is 3.2 mm). No apical septa were found. Sculpture consists of transverse rarely anastomosing ribs, which are asymmetrical in transverse cross-section. Ventral side bears only indistinct growth-lines. Conch attained minimum length 30 mm.

Occurrence

This rare species has been found only at the Biskoupky, Buchava and Hradiště localities.

Remarks

In his manuscript, Marek (1983) stated that the material collected from the above localities contained another species closely related to Alfaites romeo sp. nov., but presenting opercula with distinctly more vaulted conical shields, higher cardinal shields and a more rounded outline. He even marked the box of one specimen (NM L46646, Fig. 2D ) as “ Alfaites julia ” sp. nov., but no significant differences could be observed upon study of the available material.

Figures

Fig. 2. Alfaites romeo gen. et sp. nov. A-B. Holotype (NM L46640). A. Outer mould of internal side of operculum. B. Detail of outer mould of internal side of operculum with marked cardinal teeth. C–I. Paratypes. C. Outer mould of internal side of operculum (NM L46642). D. Outer mould of external side of operculum (NM L46646). E. Outer mould of external side of operculum (NM L46641). F. Outer mould of apertural part of conch – lateral view (NM L46645). G. Inner mould of apertural part of conch – dorsal view (NM L46645). H. Subtrigonal cross-section of conch (NM L46643). I. Outer mould of dorsal side of conch with distinct asymmetrical ribs (NM L46644). Scale = 1 mm.