Atlantemolanum González-Alvarado et al., 2019

Molano-Rendón, Arturo González-Alvarado ı Fredy & Vaz-de- Mello, Fernando Z., 2019, A new genus of dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) endemic to the Brazilian Atlantic Forest, Journal of Natural History 53 (27), pp. 1751-1765 : 1753-1757

publication ID

https://doi.org/ 10.1080/00222933.2019.1660429

DOI

https://doi.org/10.5281/zenodo.3671063

persistent identifier

https://treatment.plazi.org/id/8D45C315-FFAF-1242-FE9C-EFB7FE74FE9F

treatment provided by

Valdenar

scientific name

Atlantemolanum González-Alvarado et al.
status

gen. nov.

Atlantemolanum González-Alvarado et al. View in CoL new genus ( Figures 1 View Figure 1 (a–e)ı 2–5)

Type species

Deltochilum riehli Harold 1868 View in CoL (present designation) = Atlantemolanum riehli ( Harold 1868) View in CoL new combination ( Figure 1 View Figure 1 (a)).

Composition

Besides the type speciesı Atlantemolanum View in CoL new genus includes Deltochilum costalimai Pereira View in CoL and d ’ Andretta 1955 = Atlantemolanum costalimai View in CoL (Pereira and d ’ Andretta 1955) new combination ( Figure 1 View Figure 1 (b)).

Diagnosis

Atlantemolanum can be separated from all other genera of Scarabaeinae of the New Word by the following combination of characters: (1) mesotibiae with only one spur ( Figure 1 View Figure 1 (c)) and (2) Mesosternum with a transversal sulcus anteriorly at the meso-metasternal suture. The two species included in Atlantemolanum were originally described within the genus Deltochilum by having apical elytral tubercles in some of the interstriaeı a character present in all species of the genus Deltochilum ; however A. riehli and A. costalimai can be separated from all other species of Deltochilum ı by the following combination of characters: (1) mesotibiae with only one spur ( Figure 1 View Figure 1 (c))ı two spurs in the species of Deltochilum ; (2) hypomeron divided by a strong transverse carinaı and with a deep excavation anteriorly ( Figure 1 View Figure 1 (d) black arrow) to the carina; in the genus Deltochilum ı only the species of the subgenus Calhyboma have the transverse carinaı but anteriorly to the carina is weakly excavated; (3) pronotumı in dorsal viewı with a carina (that separates it from the hypomeron) not visible between the medial and posterior angles ( Figure 1 View Figure 1 (e) arrow)ı carina visible (in dorsal view) ( Figure 1 View Figure 1 (f) arrow) in the species of Deltochilum ; (4) meso- and metafemora marginated anteriorly and posteriorly on its ventral face ( Figures 1 View Figure 1 (c)ı 2(g – h)ı 4(h – i))ı not marginated in the species of Deltochilum .

Description

Sizeı length 9 – 12.5 mm (from anterior margin of pronotum to apex of elytra)ı humeral width 6.5 – 9.5 mm. Body oval; colour black or black with coppery reflections. Body covered by circuları ocellate punctures; body with setose puncturesı setae longest dorsally and on the femora.

Head ( Figures 2 View Figure 2 (a)ı 4(a)). Wider than long; covered with punctures separated by one diameter on the centre and the genae; vertex and between the clypealı punctures separated by less than one diameter. Posterior margin of head without carina. Clypeus bidentateı teeth acuteı each tooth separated by a U-shaped emargination; clypeo-genal suture visible; clypeus almost straight between tooth and clypeo-genal suture. Genae roundedı anterior angles of genae slightly projected. Eyes dorsally smallı dorsal interocular distance 12 times the width of one eye; eyes longer than wideı approximately two times longer than wide.

Pronotum ( Figures 1 View Figure 1 (dıe)ı 4(b)). Globuları two times wider than long; in dorsal viewı margin separating pronotum from hypomeron not visible between medial and posterior angles ( Figure 1 View Figure 1 (e) arrow); margin visible in lateral view and interrupted by punctures ( Figure 1 View Figure 1 (d) white arrow). Pronotal anterior angles projectedı slightly directed laterally; margin between anterior and medial angles of pronotum concaveı medial angle rounded; margin between medial and posterior angles of pronotum straight. Pronotal disc with punctures separated by more than one diameterı gradually larger and denser towards pronotal margins. Pronotum in the middle with a callosity near anterior margin ( Figure 1 View Figure 1 (e)). Hypomeron divided by a strong transverse carinaı with deep excavation anteriorly ( Figure 1 View Figure 1 (d) black arrow); carina completeı reaching the medial angle of pronotum.

Elytra ( Figures 2 View Figure 2 (b–d)ı 4(c–e)). With ten striaeı 9th and 10th striae completely separated from the apex to the middle of the elytronı fused from the middle to the base; striae with extended puncturesı punctures almost twice as long as wide ( Figure 2 View Figure 2 (d)ı 4(e)); strial punctures smallı almost the same width as the strial line ( Figures 2 View Figure 2 (d)ı 4(e)). 1st – 5th striae widened basallyı twice as wide as at the apex. Interstriae with rounded punctures ( Figures 2 View Figure 2 (d)ı 4(e)). 1stı 3rdı 5th and 7th interstriae with shiny callosities along elytral length; apex of elytra with tubercles on 3rd – 7th intestriae ( Figure 4 View Figure 4 (d))ı some times without tubercle on 4th insterstria ( Figure 2 View Figure 2 (c)); 7th interstriaı on humeral regionı slightly elevated ( Figures 2 View Figure 2 (b)ı 4(c)); 9th interstria carinatedı carina fine and present on the basal fourth of elytral length.

Pygidium . Triangular and convexı 1.5 times wider than long; with a transverse carina separating it from prepygidium. Pigidial punctures denserı separated by less than one diameter.

Mesosternum and metasternum ( Figures 2 View Figure 2 (e)ı 4(f)). Mesosternum narrowı in the midline lineı one-third narrower than prosternum. Mesosternum with transversal sulcus anteriorly at mesometasternal suture. Metasternum ( Figures 2 View Figure 2 (e)ı 4(f)) wideı each mesocoxa separated by approximately three times the width of one mesocoxa. Mesocoxal axis ( Figure 2 View Figure 2 (e)) slightly obliqueı almost parallel to the longitudinal body axis. Metasternal disc with longitudinal sulcus in the posterior two-thirds. Metasternum covered by punctures separated by more than one diameterı laterally and posteriorly denser and larger.

Abdomen ( Figures 2 View Figure 2 (f)ı 4(g)). With six ventrites; the first ventrite wideı measured along the midlineı as wide as the second and third ventrites combined; 2nd to 6th ventrites almost equalı measured along midlineı in width. Ventrites with puncturesı larger laterallyı gradually smaller to centre; punctures at centre two times smaller than lateral ones. 1st – 4th ventrites with punctures only at anterior half of each ventrite; 5th ventrite with punctures in the middle line and laterallyı along both anterior and posterior surfaces. Punctures between middle line and lateral ones distributed only at anterior half. Sixth ventrite with completely covered by punctures.

Legs. Protibia with three lateral teethı distributed along the apical two-fifths; with small denticles in the external margin and between the teeth; distance between apical teeth less than distance between second and third teeth; distance between second and third teeth three times the distance between apical teeth. Protibial apex straightly truncatedı with five tarsomeresı 1st and 5th twice wider than longı same length approximately; 2nd – 4th as wide as longı same length approximately. Length of 2nd – 4th combined almost same length as 1st. Profemur with dense puncturesı separated by less than one diameter.

Mesofemur ( Figures 1 View Figure 1 (c)ı 2(g)ı 4(h)) marginated anteriorly and posteriorly on its ventral face. Mesofemur with dense punctures separated by less than one diameter. Mesotibia weakly and gradually widened apicallyı width of the apex approximately oneeighth of the tibial length; mesotibial apex straightly truncated and with one large and curve spur ( Figures 1 View Figure 1 (c)ı 2(g)ı 4(h))ı spur length approximately equal to the length of the first four tarsomeres combined. Mesotibia with five triangular tarsomeresı tarsomeres 1st – 4th uniform in sizeı and the fifth twice the length of the fourth; mesotarsal claws curved.

Metafemur ( Figures 2 View Figure 2 (h)ı 4(i)) marginated anteriorly and posteriorly on its ventral face. Metafemur with punctures at anterior half twice as large as the punctures at posterior half; punctures at posterior half of femur denser than those at anterior halfı separated by less than one diameter at posterior half and by more than one diameter at anterior half. Metatibia weakly and gradually widened apicallyı width of the apex approximately oneeleventh of the tibial length; metatibial apex straightly truncated and with one curved spurı spur length approximately equal to the length of the two basal tarsomeres combined; metatibia with five triangular tarsomeresı tarsomeres 1st – 4th uniform in sizeı and the fifth twice the length of the fourth; metatarsal claws curved.

Etymology

The genus name pays homage to one of the co-authorsı the late Fredy Molano who sadly passed away during the review process of this paper. Associated with its endemicity to the Atlantic rainforestı originates the proposed name. It is male in gender.

Distribution ( Figure 5 View Figure 5 )

This new genus is so far known to be endemic to the central and southern Atlantic Forest of Brazil.

Remarks

This new genus presents one unique character among all the genera of New World Scarabaeinaeı the presence of only one mesotibial spur; all other described New World Scarabaeinae genera present two mesotibial spurs.

In the description of the A. riehli n. comb. Harold (1868) did not mention the tibial spurs; for this speciesı Paulian (1939) described only the protibial and metatibial spurs; and Pereira and d ’ Andretta (1955) stated that this species has two mesotibial spursı one three times longer than the other; howeverı in the figure of the mesotibia (Figure 28 p. 16) of Pereira and d ’ Andretta (1955) only one spur is evident. The latter was confirmed after examining the lectotype.

Pereira and d ’ Andretta (1955)ı in their description of A. costalimai n. comb. ı stated than this species has two mesotibial spursı one larger and curved and the other one smallerı however in the figure of the mesotibia (figure 18 p. 13) of Pereira and d ’ Andretta (1955) only one spur is evident; furthermoreı the holotype of this species only has one mesotibial spur.

One single mesotibial spur is a character shared between Atlantemolanum and some species of the tribes Scarabaeini ( Janssens 1940a; Harrison and Philips 2003; Zídek and Pokorný 2008) and Gymnopleurini ( Janssens 1940b; Pokorný and Zídek 2009 ı 2014 ı 2016). Howeverı this genus can be separated from species of these two tribes by the mesocoxal axis that is strongly obliqueı which contrasts with Atlantemolanum where the mesocoxae are almost parallel to the longitudinal body axis ( Figure 2 View Figure 2 (e)). Alsoı in the tribe Scarabaeini the anterior angles of the genae have a notch-like emarginationı whereas in Atlantemolanum the anterior angles of the genae are slightly projected ( Figures 2 View Figure 2 (a)ı 4(a)). The tribe Gymnopleurini is characterised by an elytral emarginationı which exposes part of the pleuron ( Pokorný and Zídek 2009)ı while the species of Atlantemolanum do not have this emargination.

Additionallyı in a recent studyı Tarasov and Dimitrov (2016) proposed two synapomorphiesı wings with: (1) RP1 posterior sclerite represents small basal appendix of RP1ı and (2) RA4 significantly thinner than RP1ı arcuate and not parallel to RA4; RA4 fused basally with RP1ı for the tribe Deltochiliniı characters which are present in Atlantemolanum . Given thisı Atlantemolanum is placed in Deltochilini sensu Tarasov and Dimitrov (2016) .

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Scarabaeidae

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