This species was described in 1972, it is, or maybe was, endemic to the island of Saint Helena.
The species reaches a length of about 1,7 to 1,8 cm; it is mainly brown colored and differs from its close relative, the Eudoxus Scarab Beetle (Mellissius eudoxus Wollaston) in some characters including a less arched pronotum. [1]
The species was apparently not found during the most recent field searches and is probably extinct.
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References:
[1] S. Endrödi: Monographie der Dynastinae (Col. Lamellicornia, Melolonthidae) 4. Tribus: Pentodontini der äthiopischen Region, III. In: Entomologische Arbeiten aus dem Museum G. Frey Tutzing bei München 27: 118-282. 1976
This species was endemic to the island of Saint Helena, where it apparently was very common in former times; its larvae were called hog-worms and were thought to cause great damage to the grasslands by feeding on the roots of the grasses.:
“Indeed we met with the eudoxus almost universally throughout the rather elevated central and south-western parts of the island (particularly in the vicinity of Cason’s, High Peak, and West Lodge), and more sparingly even in the northern ones, whereas of the adumbrates I did not procure so much as a single example during our six months’ sojourn in the island; so that, if the “hog-worms” do really “play so important a part in the destruction of the grass on the high lands, by feeding on its roots, that large patches, and sometimes whole fields, are laid bare,” I suspect that it must be the M. eudoxus, and not the comparatively rare adumbrates, which is mainly responsible for the damage.” [1]
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The Eudoxus Scarab Beetle was apparently not found during the most recent field searches and appears to be possibly extinct.
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The depiction below shows another species of that genus, the Shaded Scarab Beetle (Mellissius adumbrates Wollaston), which apparently still survives on the island.
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References:
[1] T. Vernon Wollaston: Coleoptera Sanctae-Helenae. London: John Van Voorst, Paternoster Row 1877
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Shaded Scarab Beetle (Mellissius adumbratus)
Depiction from: ‘John Charles Meliss: St. Helena: A Physical, Historical, and Topographical Description of the Island, including its Geology, Fauna, Flora, and Meteorology. London: L. Reeve & Co. 1875’
The Small Rodrigues Rhinoceros Beetle was described in 1876, it is only known from the type specimen, a female (or from two specimens, according to other sources).
The species reached a length of 2,5 cm; “The elytra are covered with rather large horseshoe punctures, among which may be traced the usual two pairs of punctured lines; the surface between the large punctures has small punctures scattered here and there.” [1]
The species is now considered extinct.
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References:
[1] Charles O Waterhouse: New species of coleoptera from the island of Rodriguez, collected by the naturalists accompanying the Transit-of-Venus Expedition. The Annals and Magazine of Natural History, Zoology, Botany, and Geology 4(18): 105-121. 1876
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Photo from: ‘Sergio M. Latorre; Matthias Herrmann; M. J. Paulsen; Christian Rödelsperger; Andreea Dréau; Waltraud Röseler; Ralf J. Sommer; Hernán A. Burbano: Museum phylogenomics of extinct Oryctes beetles from the Mascarene Islands. Cold Spring Harbor Laboratory 2020’
The Tar Pit Scarab was described in 1946; it is known only based on subfossil remains that were found in the Late Pleistocene La Brea tar pits in Los Angeles, California, USA; its closest living relatives can be found today in Arizona, USA and in Mexico, for example the Scooped Scarab (Onthophagus hecate (Panzer)) (see photo).
The beetle vanished from California along with the disappearance of its food source, the dung of large plant-eating mammals, which again died out due to the drying of the climate at the border of the Late Pleistocene/Early Holocene
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References:
[1] Arthur V. Evans; James N. Hogue: Introduction to California beetles. University of California Press 2004
