Scarabaeus (Pachysoma) fitzsimonsi (Ferreira, 1953)

Harrison, J. Du G., Scholtz, C. H. & Chown, S. L., 2003, A revision of the endemic south-western African dung beetle subgenus Scarabaeus (Pachysoma) MacLeay, including notes on other flightless Scarabaeini (Scarabaeidae: Scarabaeinae), Journal of Natural History 37 (3), pp. 305-355 : 338-339

publication ID	https://doi.org/ 10.1080/713834683
persistent identifier	https://treatment.plazi.org/id/03A60308-FFC4-3239-FE29-FA60FB2A82D0
treatment provided by	Carolina
scientific name	Scarabaeus (Pachysoma) fitzsimonsi (Ferreira, 1953)
status

Treatment

( figures 10 View FIGS , 27 View FIGS , 45, 66)

Pachysoma fitzsimonsi Ferreira, 1953a: 20 View in CoL ; Ferreira, 1961: 22; Ferreira, 1966: 58; Ferreira, 1969: 21; Holm and Scholtz, 1979: 234. Holotype: Namtib, Namibia (1 3 TMSA).

Scarabaeus fitzsimonsi (Ferreira) : Mostert and Holm, 1982: 275.

Diagnosis. Clypeus quadridentate, outer clypeal teeth reduced in size ( figure 27 View FIGS ); protibia hardly dimorphic with simple protibial spurs ( figure 45); sub-elytral ridge usually present but faint; inner metatarsal claws slightly shorter than outer metatarsal claw; metatarsal claws shorter than last tarsal segment; male genitalia in figure 66a, b.

Distribution, habitat and conservation. This species occurs east of the central dune area ( figure 10 View FIGS ), on the sandy flats of the pro-Namib ( Holm and Scholtz, 1979). S. (P.) fitzsimonsi occurs within the Namib-Naukluft Park.

Comments on locality data. The single record from the far east of the Namib Desert (23 ° 53 ∞ S, 16 ° 07 ∞ E) is a considerable range extension northwards for the distribution of S. fitzsimonsi . Suspicion of a new species was unconfirmed as the single male matches S. (P.) fitzsimonsi in all aspects, including the faint sub-elytral ridge and genitalia typical of the species. However, this locality record requires confirmation.

Morphological variation. Two females, one each from Haibvlakte and Numabis Pan have no sub-elytral ridge, a character used by Holm and Scholtz (1979) to separate S. rotundigenus from S. (P.) fitzsimonsi . A male from Haibvlakte does, however, have a sub-elytral ridge and genitalia typical of S. fitzsimonsi . This suggests possible dimorphism in expression of the sub-elytral ridge, but no other S. (P.) fitzsimonsi females examined confirm this possibility.

Biology. The biology of S. (P.) fitzsimonsi is unknown. However, based on the hind leg morphology their foraging behaviour and food choice should not differ from that of S. (P.) rodriguesi (dung pellets) or S. (P.) denticollis (dung pellets and detritus). The short metatarsal claws of S. (P.) fitzsimonsi suggest pellet feeding rather than detritus feeding and adaptation to a firm substrate rather than soft dune sand (see Koch, 1961, 1962a, 1962b, 1969; Lawrence, 1969; Newlands, 1972; Endrödy-Younga, 1982; Henschel, 1997 for evidence of this morphological change in other taxa). S. (P.) fitzsimonsi is thus probably predominately a dry pellet feeder. Evidence to support this claim comes from Davis (1999, personal communcation) who recalls finding sheep pellets in the burrows when he excavated the Weissenborn specimens. The larvae are unknown.

Comments. Easily confused with S. (P.) rotundigenus but S. (P.) fitzsimonsi is distinguished by having simple protibia in both sexes, short metatarsal claws and apical insertion of the mesotarsi and metatarsi on the tibia. The sub-elytral ridge in S. fitzsimonsi cannot be used as the only character to distinguish between these two species (see Morphological variation).

Types. All the types are in the TMSA collection. The holotype and allotype have no date on their locality label, but the paratypes are dated 17 September 1950 .

Type material examined (S4 specs [4], 2 ♀ 2 3, 2 3 diss.). NAMIBIA: HOLOTYPE 3, Pachysoma fitzsimonsi Ferreira : Namtib, 70m NW of Aus, (ca. 25.52.05S 16.52.05E), Gt. Namaqualand, (no date), C.Koch, G.van Son / Holotipo Pachysoma FitzSimonsi , 3, M.C.Ferreira, 1951 (written by Ferreira in red ink on white card, surrounded by a black rectangular border) / Holotypus Pachysoma fitzsimonsi, M.C.Ferreira sp.n. (written by Endrödy-Younga on to TMSA Ferreira label), (aedeagus and pygidium on a separate pin), (1 3 TMSA); idem, but / Alotipo Pachysoma FitzSimonsi , ♀, M.C.Ferreira, 1951 / Allolotypus Pachysoma fitzsimonsi, M.C.Ferreira sp.n., (1 ♀ TMSA). PARATYPES: Aus, Gt. Namaqualand, (26.41S 16.16E), 17.ix.1950, C.Koch, G.van Son / Para-Tipo Pachysoma FitzSimonsi, M.C.Ferreira , (1 ♀ 1 3 TMSA).

Additional material examined from Namibia (S26 specs [29], 11 ♀ 15 3, 5 3 diss.) .