Talpina Hagenow, 1840

Gaaloul, Nadia, Uchman, Alfred, Ali, Syrine Ben, Janiszewska, Katarzyna, Stolarski, Jarosław, Kołodziej, Bogusław & Riahi, Sami, 2023, In vivo and post-mortem bioerosion traces in solitary corals from the upper Pliocene deposits of Tunisia, Acta Palaeontologica Polonica 68 (4), pp. 659-681 : 674-675

Ichnogenus Talpina Hagenow, 1840

Type ichnospecies: Talpina ramosa Hagenow, 1840 , lower Maastrich- tain chalk, Rügen , Germany .

Emended diagnosis. —Narrow, tubular borings in lithic or hard skeletal substrates, forming multi-branching tunnel systems with apertures towards the exterior. Tunnels with circular to oval cross-section, straight to strongly curved; short side branches towards apertures often developed near branching points of the main tunnel system. Tunnels may anstomose.

Remarks.— Conchotrema Teichert, 1945 , was subjectively synonymized with Talpina Hagenow,1840 ,byWisshaketal. (2019). Their possible synonymization has been announced since longer ( Voigt 1972; Bromley 2004), but Bromley and D’Alessandro (1987) suggested that Conchotrema is smaller, less regular, and shows an anastomosing course of tunnels (see also Stiller 2005). Nevertheless, the differences seem to be not principal at the ichnogenus level. Both ichnogenera fit well to the diagnosis of the ichnofamily Talpinidae Wisshak, Knaust, and Bertling, 2019, typified by Talpina Hagenow, 1840 , which reads “Branched cylindrical borings that may an anstomose” ( Wisshak et al. 2019: 24). The most recent diagnosis of Talpina by Stiller (2005) reads: “Narrow, tubular borings in hard substrates with overall morphology changing astogenetically from short, simple borings to extensive, multi-branching tunnel systems with numerous apertures towards exterior (borings of pseudocolonies); completely buried in the substrate. Tunnels with circular to oval cross-section, straight to strongly curved; short side branches towards apertures often developed near branching points of the main tunnel system.” This diagnosis contains a lot of interpretative elements. Therefore, it is emended. However, a better understanding of all the differences between Talpina and other members of the ichnofamily Talpinidae, which is beyond the scope of this paper, may necessitate of a new emendation. Talpina and its synonym Conchotrema are interpreted as borings produced by pseudocolonies of phoronids ( Voigt 1972, 1975). It is known since the Early Devonian (Voigt 1967; Stiller 2005).

Talpina cf. hackberryensis ( Thomas, 1911) Fig. 14 .

Material.— INGUJ 265P164, 168; curved, branched grooves on the surface of coralla; El Melah stream section, the upper part of the Argiles de Sidi Barka Formation (upper Pliocene) of Tunisia.

Description. —Straight, slightly or strongly curved, dichotomously or irregularly branched smooth furrows on the surface of corallum, 0.1–0.15 mm wide. Some of the furrows pass into very shallow subsurface tunnels of the same size, which are filled with fine clastic material. The furrows/ tunnels run mostly along or obliquely to the corallum, some of them anastomosing or missing on slightly different levels. The distance between the braches ranges from 0.5 to 4 mm. Close to the furrows/tunnels, some circular/oval pits of the same size are dispersed.

Remarks. — Bromley and D’Alessandro (1987) synonymized Clionolithes canna Price, 1916 , and Conchotrema tubulosa Teichert, 1945 , under Conchotrema Teichert, 1945 . Further, Wisshak (2017) followed an unpublished PhD thesis by Plewes from 1996, who synonymized Clionolithes canna Price, 1916 , and Cliona hackberryensis Thomas, 1911 , un- der the ichnogenus Talpina Hagenow, 1840 . This taxonomic treatment is followed here. However, the distances between branches are larger than in the diagnosis of C. canna by Bromley and D’Alessandro (1987), and the apertures (visible as circular/oval pits) are numerous. On the other hand, they are very similar to Talpina tubulosa ( Teichert, 1945) visible in the Permian Spirifer valves from Western Australia ( Teichert 1945: pl. 2: 1, 2). As ichnospecies of Talpina are pending a revision, the determination is left in the open nomenclature without a diagnosis.

Figures

Fig. 14. Talpina cf. hackberryensis (Thomas, 1911), a domichnion produced by phoronids in the skeleton of caryophylliid coral Ceratotrochus (Edwardsotrochus) duodecimcostatus (Goldfuss, 1826), from the El Melah stream section, the upper part of the Argiles de Sidi Barka Formation (upper Pliocene) of Tunisia. A. INGUJ265P168. B. INGUJ265P164.