Tessaradoma boreale (Busk, 1860)

(Fig. 11D)

Onchopora borealis Busk, 1860: 213, pl. 28, figs 6-7.

Porina borealis – Hincks 1880: 229, pl. 31, figs 4-6. — Neviani 1891: 120, pl. 4, figs 4-5.

Tessaradoma boreale – Gautier1962: 222. — Hayward & Ryland 1979: 242, text-fig. 104. — Moissette 1988: 123, pl. 20, fig. 5. — Zabala & Maluquer 1988: 142, text-fig. 343. — El Hajjaji 1992: 225, pl. 13, fig. 2. — Pouyet & Moissette 1992: 53, pl. 7, fig. 3. — Moissette & Spjeldnaes 1995: 790, pl. 3, fig. 5.

OCCURRENCE. — Middle Miocene: France. Late Miocene: Morocco (El Hajjaji 1992), Algeria (Moissette 1988), Calabria. Pliocene: northern Italy, Sicily (Pouyet & Moissette 1992). Pleistocene: Sicily, Calabria (Rosso 2005), Rhodes (Moissette & Spjeldnaes 1995), Karpathos (Moissette et al. 2017). Recent: Atlantic (western, but mostly eastern), Arctic, Mediterranean. T. boreale is predominantly a deep-water (Cheetham 1972), cryophilic (max. 13° C) species (60-3500 m in the Atlantic, 50-1300 m in the Mediterranean).

DESCRIPTION

Vinculariiform colony. Slender cylindrical branches. Oval, elongate zooids arranged in alternating series. Frontal smooth and finely striated, with a row of marginal pores. A spiramen is situated proximally to the semicircular aperture, which bears a short tubular peristome. Avicularia (1-3) and ovicell not observed.

REMARKS

T. gracile (Sars) is generally considered as a synonym of T. boreale.