Onthophagus velutinus, Horn, 1875

Kohlmann, Bert & Solís, Ángel, 2025, A review of the species groups of the Western Hemisphere Onthophagus Latreille (Coleoptera: Scarabaeidae: Scarabaeinae) using COI barcoding and gene trees, Zootaxa 5604 (4), pp. 401-447 : 429-430

Onthophagus velutinus species group*.

This group is diagnosed by a pronotal disc distinctly tuberculate; clypeus slightly emarginate; surface of pronotum and (or) elytra finely alutaceous. Male with two straight and erect horns at vertex ( Figs. 5.19 –20); male protibia short and stout ( Figs. 1.29 –30); male protibial spur inwardly bent at apex ( Figs. 1.29 –30); male protibial apex with some short setae ( Figs. 1.29 –30); metafemur long and slender ( Figs. 2.29 –30); male pronotum with a well-developed central gibbosity ( Figs. 5.19 –20); apex of parameres well developed and defined. Females with carina of vertex nearly straight.

Zunino & Halffter (1997: 159) included O. velutinus Horn as part of the O. mexicanus species group without giving any justification for this decision. Later, Zunino (2003) considered O. cartwrighti Howden to be in an incertae sedis species group. Subsequently, Moctezuma & Halffter (2019) suggested that O. cartwrighti should be included within the O. mexicanus species group due to its close relationship to O. velutinus . We disagree with these opinions because these species have a different Bauplan (from the German, Bauplan (s.) [Baupläne, pl.], body plan, a suite of characters shared by a group of phylogenetically related animals at some point during their development; Willmore 2012) from the O. mexicanus species group.

While the mtDNA analyses suggested a relationship between the O. velutinus and O. mexicanus species groups ( Figs. 1–2 , 8–9 ), the external morphological Bauplan between these two groups is entirely different. The O. velutinus species group, contrary to the O. mexicanus species group, does not have pronotal horns and no short and thick metafemora ( Figs. 2.29 –30) and presents very characteristic and almost parallel long vertex horns ( Figs. 5.19 –20). Howden & Cartwright (1963: 107) indicated that O. velutinus is quite distinct from other Western Hemispheric Onthophagus species and seemed restricted to Neotoma Say & Ord ( Rodentia : Cricetidae ) nests. We suggest that O. cartwrighti and O. velutinus form a new species group, the O. velutinus species group, distributed in the Southwestern United States of America and the Baja California Peninsula.

Figures

FIG. 5. Onthophagus important characters marked with arrows (details discussed in the text). 1, O. atriglabrus; 2, O. orphnoides; 3, O. propraecellens; 4, O. genuinus; 5, O. andersoni; 6, O. crinitus; 7, O. gazellinus; 8, O. onthochromus; 9. O. landolti; 10, O. anthracinus; 11, O. championi; 12, O. cynomysi; 13, O. orpheus orpheus; 14, O. hoepfneri; 15, O. acuminatus; 16, O. incensus; 17, O. cyanellus; 18, O. sanpabloetlorum; 19, O. cartwrighti; 20, O. velutinus. See Table 7 for the author names of the species listed.

FIG. 1. Neighbor-joining tree for the Western Hemisphere Onthophagus species, based on K2P genetic distances comparisons between COI-5P mitochondrial barcoding sequences. Figs. 23–25 belong to the O. eulophus species group. Figs. 44 and 63 are not assigned to any species group. The male protibiae of the following species are depicted: 1, O. acuminatus; 2, O. batesi; 3, O. incensus; 4, O. nitidor; 5, O. stockwelli; 6, O. striatulus striatulus; 7, O. tristis; 8, O. basicarinatus; 9, O. hircus; 10, O. marginicollis; 11, O. nyctopus; 12, O. onorei; 13, O. osculati; 14, O. ptox; 15, O. ranunculus; 16, O. atriglabrus; 17, O. genuinus; 18, O. rostratus; 19, O. sharpi; 20, O. tapirus; 21, O. villanuevai; 22, O. violetae; 23, O. anewtoni; 24, O. arnetti; 25, O. browni; 26, O. championi; 27, O. guatemalensis; 28, O. mexicanus; 29, O. cartwrighti; 30, O. velutinus; 31, O. alluvius; 32, O. altivagans; 33, O. anthracinus; 34, O. brachypterus; 35, O. chryses; 36, O. landolti; 37, O. lecontei; 38, O. schaefferi; 39, O. concinnus; 40, O. cynomysi; 41, O. hecate hecate; 42, O. medorensis; 43, O. orpheus orpheus; 44, O. polyphemi sparsisetosus; 45, O. chevrolati; 46, O. cyanellus, 47, O. hippopotamus; 48, O. oaxacanus; 49, O. reyesi; 50, O. salvadorensis; 51, O. sanpabloetlorum; 52, O. skelleyi; 53, O. subtropicus; 54, O. totonicapanus; 55, O. vespertilio; 56, O. crinitus; 57, O. gazellinus; 58, O. onthochromus; 59, O. aciculatulus; 60, O. coscineus; 61, O. hoepfneri; 62, O. igualensis; 63, O. lebasi; 64, O. pennsylvanicus; 65, O. subanaeus; 66, tuberculifrons; 67, O. barreti; 68, O.breviconus; 69, O. contrapositus; 70, O. dicranius; 71, O. dorsipilulus; 72, O. humboldti; 73, O. kohlmanni; 74, O. micropterus; 75, O. neomirabilis; 76, O. orphnoides; 77, O. petenensis; 78, O. subcancer; 79, O. andersoni; 80, O. belorhinus; 81, O. grataehelenae; 82, O. limonensis; 83, O. maya; 84, O. praecellens; 85, O. propraecellens; 86, O. rhinolophus; 87, O. rhinophyllus; 88, undescribed species of Onthophagus; 89, O. viridivinosus; 90, O. xanthomerus. See Table 2 for an explanation of the specimen codes. See Table 7 for the author names of the species listed.

FIG. 2. A summarized neighbor-joining tree for Western Hemisphere Onthophagus species, based on K2P genetic distances comparisons between COI-5P mitochondrial barcoding sequences. Figs. 23–25 belong to the O. eulophus species group. Figs. 44 and 63 are not assigned to any group. The male metafemora of the following species are depicted: 1, O. acuminatus; 2, O. batesi; 3, O. incensus; 4, O. nitidor; 5, O. stockwelli; 6, O. striatulus striatulus; 7, O. tristis; 8, O. basicarinatus; 9, O. hircus; 10, O. marginicollis; 11, O. nyctopus; 12, O. onorei; 13, O. osculati; 14, O. ptox; 15, O. ranunculus; 16, O. atriglabrus; 17, O. genuinus; 18, O. rostratus; 19, O. sharpi; 20, O. tapirus; 21, O. villanuevai; 22, O. violetae; 23, O. anewtoni; 24, O. arnetti; 25, O. browni; 26, O. championi; 27, O. guatemalensis; 28, O. mexicanus; 29, O. cartwrighti; 30, O. velutinus; 31, O. alluvius; 32, O. altivagans; 33, O. anthracinus; 34, O. brachypterus; 35, O. chryses; 36, O. landolti; 37, O. lecontei; 38, O. schaefferi; 39, O. concinnus; 40, O. cynomysi; 41, O. hecate hecate; 42, O. medorensis; 43, O. orpheus orpheus; 44, O. polyphemi sparsisetosus; 45, O. chevrolati; 46, O. cyanellus, 47, O. hippopotamus; 48, O. oaxacanus; 49, O. reyesi; 50, O. salvadorensis; 51, O. sanpabloetlorum; 52, O. skelleyi; 53, O. subtropicus; 54, O. totonicapanus; 55, O. vespertilio; 56, O. crinitus; 57, O. gazellinus; 58, O. onthochromus; 59, O. aciculatulus; 60, O. coscineus; 61, O. hoepfneri; 62, O. igualensis; 63, O. lebasi; 64, O. pennsylvanicus; 65, O. subanaeus; 66, tuberculifrons; 67, O. barreti; 68, O.breviconus; 69, O. contrapositus; 70, O. dicranius; 71, O. dorsipilulus; 72, O. humboldti; 73, O. kohlmanni; 74, O. micropterus; 75, O. neomirabilis; 76, O. orphnoides; 77, O. petenensis; 78, O. subcancer; 79, O. andersoni; 80, O. belorhinus; 81, O. grataehelenae; 82, O. limonensis; 83, O. maya; 84, O. praecellens; 85, O. propraecellens; 86, O. rhinolophus; 87, O. rhinophyllus; 88, undescribed species of Onthophagus; 89, O. viridivinosus; 90, O. xanthomerus. See Table 2 for an explanation of the specimen codes. See Table 7 for the author names of the species listed.

FIG. 8. Maximum-likelihood gene tree for the Western Hemisphere Onthophagus species. Bootstrap values were calculated using the rapid bootstrap algorithm of RaxML under the GTRCAT model with 10,000 replicates and run on the CIPRES portal. See Table 2 for an explanation of the specimen codes.

FIG. 9. Maximum-likelihood gene tree for the Western Hemisphere Onthophagus species, partitioned by codon. An IQ-TREE analysis was performed using default parameters for the Invertebrate Mitochondrial Code. See Table 2 for an explanation of the specimen codes.