Rove Beetles, Staphylinidae, are considered to be the most specious group of Animals alive today, with 66 928 described species in 35 subfamilies. The group appeared around the beginning of the Jurassic, with the majority of the extant subfamilies having appeared by the end of that period, and with significant ongoing diversification through the Cretaceous. The subfamily Mycetoporinae contains about 444 described species in 16 genera. It has a rather limited fossil record, with four known species from the Early Cretaceous of Russia and China, Cuneocharis elongata and Ryvkinius gracilis from the Daya Formation, and Undiatina pilosa from the Semyon Formation, all from Russia, and Glabrimycetoporus amoenus from the Yixian Formation of China, and several specimens assigned to the genera Lordithon and Mycetoporus from the Eocene Florissant Formation of the United States.
In a paper published in the journal Insect Systematics & Evolution on 29 March 2024, Sandiso Mnguni of the Evolutionary Studies Institute and Centre of Excellence in Palaeosciences at the University of the Witwatersrand, and Ian James McKay and Shaw Badenhorst, also of the School of Geosciences at the University of the Witwatersrand, describe a new species of Mycetoporine Rove Beetle from the Cretaceous Orapa Diamond Mine deposits of Botswana.
The Opara Diamond mine exploits two diamondiferous kimberlite pipes, (igneous deposits in which material from deep within the Earth is extruded upwards though existing deposits) which cut through Late Cretaceous deposits, reaching the surface and forming a volcanic crater in the Turonian, about 93.1 million years ago. Mining operations here have formed a large oval pit, which, as well as the kimberlite pipes, has exposed a series of lacustrine sediments preserving fossil Plants and Insects.
The new species is given the name Cretafrica orapensis, where 'Cretafrica' is a combination of Cretaceous and Africa, and 'orapensis' means 'from Orapa'; Orapa itself means 'the resting place of Lions' in the Sesarwa language, a name originally given to a cattle post near the site where diamonds were discovered. The species is described from a single specimen, a well-preserved impression fossil, and both dorsal and ventral structures are superimposed, and thus visible on top of each other. A second, smaller Beetle is also preserved on the same slab, which is probably a Hydroscaphid Water Beetle.
The specimen is 4.92 mm long and 1.58 mm wide. The head is elongated and triangular, with small oval eyes towards the rear. The antennae are poorly preserved, but probably have eleven segments and were located anterior to the eyes. Mandibles, maxillary and maxillary palps are visible, but poorly preserved. The pronotum (forepart of the thorax) is hard to interpret, as it is partially covered by sediment. The Elytra cover less than a third of the body, leaving six abdominal segments exposed.
Finding a member of the Mycetoporinae at Orapa has significant implications for the history of the group. Four previous Lower Cretaceous specimens have been described from three different localities, though these were all on the eastern part of the Eurasian landmass. The discovery of a specimen from Southern Africa, significantly increases the geographical range of Early Cretaceous Mycetoporine Rove Beetles, indicating that the group must have been in existence for long enough to achieve a near global distribution by this time.
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