Bivalvia
Naiadites devonicus Locality: Waterloo Farm Bivalve molluscs found at Waterloo Farm were ascribed to the genus Naiadites (1). Naiadites is considered to have been epifaunal, living in attachment to submerged vegetation. This is the oldest example of the genus and its occurrence at Waterloo Farm in rocks of Devonian age has some interesting palaeogeographic implications. The bivalves have been diagnosed to a new species, Naiadites devonicus (2). Prior to its discovery in South African strata, Naiadites, a non-marine genus of bivalve was known exclusively from the Carboniferous of Laurussia (Eurasia and North America). Scholze and Gess (2017) hypothesized that this genus of bivalve was adapted to cool conditions on the southern shores of Gondwana. Global cooling at the end of the Devonian Period facilitated the spread of this cold adapted taxon into lower latitude regions. Undescribed material
Locality: Coombs Hill Bivalve molluscs discovered in shale lenses at Coombs Hill are completely different to those found at Waterloo Farm, including several kinds of hard shelled and soft shelled forms (3), which await taxonomic analysis. Some of them, such as those illustrated below, were infaunal deposit feeders, as evidenced by the trace fossils that they produced. Further reading:
1) Scholze, F., & Gess, R. W. (2017). Oldest known naiaditid bivalve from the high-latitude Late Devonian (Famennian) of South Africa offers clues to survival strategies following the Hangenberg mass extinction. Palaeogeography, palaeoclimatology, palaeoecology, 471, 31-39. 2) Scholze, F., & Gess, R. W. (2021). Late Devonian non-marine Naiadites devonicus nov. sp.(Bivalvia: Pteriomorphia) from the Waterloo Farm Lagerstätte in South Africa. Geobios, 69, 55-67. 2) C. Harris, R.W. Gess, C.R. Penn-Clarke, B.S. Rubidge (2021). Coombs Hill: a Late Devonian fossil locality in the Witpoort Formation (Witteberg Group, South Africa). S. Afr. J. Sci., 117 (2021), pp. 1-6. |