Ovummuridae (calcareous microfossils) from the Much Wenlock Limestone Formation, Shropshire, UK

Abstract

Ovummuridae are calcareous, egg-shaped microfossils with an unknown taxonomic affinity. Their limited observation is due to their occurrence only within exceptionally preserved carbonate rocks that have undergone little to no diagenesis or aggrading neomorphism. The Much Wenlock Limestone Formation (Homerian) is famous for its exceptionally preserved and diverse fossil biota, but Ovummuridae have not been previously observed and reported from the formation. This paper introduces the population of Ovummuridae from the off-reef tract limestones of The Much Wenlock Limestone Formation, Shropshire, UK. The authors analysed 124 polished and etched thin sections using reflected light microscopy to detect the presence of Ovummuridae. A total of 6591 ovummurids were identified, including observations of several previously undescribed morphotypes of Ovummuridae. Three new genera, Munneckella, Natantesprifmata and Hartonella , and subsequently four new species, Minourella wenlockiensis, Munneckella tribuscamera, Natantesprifmata rogersi and Hartonella oblonga , are introduced. The implications of this study suggest that reflected light microscopy is an effective and efficient method for observing calcareous microfossils. Ovummuridae may be more abundant than previously reported, their stratigraphic and palaeogeographic range is further extended, and it is highlighted that the off-reef tract may have been the microfossils’ preferred environment