Pennsylvanian sponge from the Mecca Quarry Shale, Carbondale Group (Indiana, USA) and the paleobiogeographic distribution ofTeganiellain the paleoequatorial region of Laurentia

Abstract

The sponges may be the oldest group of Metazoa, with a long and successful evolutionary history. Despite their intermittent fossil record quality, the group has been considered reliable for paleoecological and paleobiogeographic analyses because they have inhabited various types of aquatic environments, forming a significant part of benthic communities. We have presented a detailed description of a new species from the genus Teganiella, Teganiella finksi new species, which expands the chronologic range and classifies the genus as endemic to the paleoequatorial regions of Laurentia associated with arid climate conditions linked to hypersaline periods. Combining the paleoecological and paleoenvironmental features of the Teganiella species, our findings also suggest a trend toward more closed-inlet conditions, which may be related to competition and/or specific habitat supplies, for example, heavy metals such as vanadium, zinc, and molybdenum.UUID: http://zoobank.org/12901a63-7cd5-4207-ac7a-0ce12649fcaf

Teganium (Porifera, Hexactinellida) from the Middle Ordovician Castle Bank fauna of Avalonia (Wales, UK)

“…The unweathered state of the material obscures many of the fine details of the skeleton, which cannot therefore be compared in detail with other species. The same is true for previously described species (Mouro et al, 2019), however, and the key characters are preserved well enough to allow an unambiguous assignment to the genus. The species is left in open nomenclature because the sample size is too small to reject the possibility of an extreme variation of shape within T. avalonensis sp.…”

“…nov.; questionably also Tl. finksi Mouro et al, 2019. Remarks. Separation of Teganiella from Teganium is highly problematic and is here considered invalid.…”

“…In their species Teganiella finksi, Mouro et al (2019) noted that although no osculum was visible in the moderately poor material, some specimens have a flattened summit that may indicate its presence and position; this is entirely normal for a laterally compressed reticulosan. Given the requirement for at least one exhalent opening in order for the sponge to function, this apparent lack of any terminal aperture is probably due to inconvenient orientation of compression in a globose sponge with a strongly narrowed osculum, to the extent that it is not clearly visible.…”

“…An assessment of previously known species of Teganiella (here transferred to the senior synonym Teganium) was provided by Mouro et al (2019), who erected the species Tl. finksi.…”

“…Teganium heathi (Rigby, 1986) appears to show no marginalia (a possible taphonomic artefact) and also possessed coarser body wall spicules, and meridional tracts of spicules or spicule rays that are not present in other species. The species described as T. finksi (Mouro et al, 2019) lacks any visible osculum or marginalia and includes much coarser spicules, in some cases up to 2 mm across.…”