First fossil sponge from Antarctica and its paleobiogeographical significance

Abstract

Laocoetis piserai n. sp. (Hexactinellida, Porifera) from the mid-Cretaceous (i.e., Albian–Cenomanian) of James Ross Island is the first record of a fossil sponge from Antarctica. This new occurrence of a formerly widespread genus was restricted to relatively deep waters on the margins of an active volcanic arc. Its occurrence in Antarctica is further evidence that the genus Laocoetis underwent a dramatic reduction in its geographic range through the Cenozoic. The only living species of the genus at the present day is Laocoetis perion from Madagascar.

Between the Alb and the Alps – The fauna of the Upper Cretaceous Sandbach Formation (Passau region, southeast Germany)

“…These animals, being a very conservative group since the Mesozoic, are important palaeobathymetric indicators (e.g., Oakley 1938, Reid 1968, Krautter 1997, Vodrážka & Crame 2011. Based on comparison with fossil and recent analogues, the presence of hexactinosidan and lychniscosidan hexactinellids suggests sedimentation below the storm wave base, i.e., a minimum depth of 50-100 m. Although ecological demands of sponges with rigid skeletons could have been slightly different in the Late Cretaceous, it should be noted that in Recent environments hexactinosidan hexactinellids are almost completely absent from waters shallower that 100 m (Finks & Rigby in Kaesler 2003).…”

“…", but separated his species because of (1) the lack of parietal oscula on branching outgrowths and (2) the seemingly irregular arrangement of canal openings. Nonetheless, scarcity to absence of parietal oscula, especially on tubular outgrowths, as well as a seemingly irregular arrangement of canal openings was also observed in Hillendia bohemica (Reid 1964, Vodrážka 2005). Order Lychniscosida Schrammen, 1903Family Neoaulocystidae Zhuralevleva, 1962 Tremabolites sp.…”

Calcareous nannofossils from the Upper Cretaceous of northern James Ross Island, Antarctica: a pilot study

“…In par tic ular, con glom er ates, tuffitic sand stones and siltstones of the Kotick Point, Whisky Bay and Hid den Lake for ma tions are almost bar ren of orig i nal calcitic/aragonitic shells. On the other hand, si li ceous macrofossils are well-pre served (Vodrážka and Crame, 2011), sug gest ing that car bon ate dis so lu tion played an im por tant role dur ing for ma tion of these strata.…”

First record of chambered hexactinellid sponges from the Palaeozoic

“…In general, hexactinellids are indicative of deep water environments, not only in the Palaeozoic but also in the Meso-and Cenozoic (e.g., Wendt et al 1989;Pratt 1995;Krautter 1997). In Recent environments, the order Hexactinosida proliferate in water depths between 100 and 6860 metres and range from the Arctic to Antarctic (e.g., Vodrážka and Crame 2011).…”