Collagenus Ratcliffe and Hardy

Ratcliffe, Brett C. & Hardy, Martin, 2005, Collagenus dasysternus, A New Genus And Species Of Dynastinae From Eastern Venezuela With A Key To The New World Genera Of Pentodontini (Coleoptera: Scarabaeidae: Dynastinae), The Coleopterists Bulletin 59 (1), pp. 143-150 : 144-149

publication ID

https://doi.org/ 10.1649/0010-065x(2005)059[0143:cdanga]2.0.co;2

persistent identifier

https://treatment.plazi.org/id/03F787E6-FF83-9928-9008-725CFC2CFF31

treatment provided by

Carolina

scientific name

Collagenus Ratcliffe and Hardy
status

gen. nov.

Collagenus Ratcliffe and Hardy , new genus

Type Species. Collagenus dasysternus Ratcliffe and Hardy , new species, here designated.

Description. Scarabaeidae , Dynastinae , Pentodontini . Form: Suboval, pronotum widest at middle, elytra widest past middle.Length of only known specimen 20.1 mm. Color: Light and dark reddish brown. Head: Frons at center with weakly elevated, flattened boss. Frontoclypeal carina strong, elevated completely from side to side. Clypeus with apical rim swollen, strongly reflexed; venter of clypeus greatly swollen and plump. Mandibles small, subtriangular, completely hidden beneath clypeus. Mentum strongly swollen and protuberant ventrally. Pronotum: Surface completely, moderately punctate. Elytra: Surface with 5 distinctly furrowed striae (2 double rows plus 1 sutural stria). Pygidium: Surface completely, moderately punctate, strongly convex. Legs: Legs with moderately dense, long, yellowish brown setae. Foretibia tridentate; apical tooth slightly removed, larger, curved; apex obliquely truncate. Apices of meso- and metatibiae each with fringe of stout bristles. Tarsi and claws slender. Venter: Thoracic sternites with dense, long, yellowish brown setae. Prosternal process a small, rounded protuberance. Abdominal sternites shiny, glabrous.

Diagnosis. Collagenus can be easily distinguished from similar genera because of the unique form of the greatly thickened rim on the broadly parabolic clypeal apex, ventrally protuberant mentum, strong frontoclypeal carina, absence of tubercles or a fovea on the pronotum, long tarsi, densely setose thoracic sternites, small rounded prosternal process, and the crenulate apex of the posterior tibiae.

Etymology. One of the most striking features of this new genus is the greatly swollen apical rim and venter of the clypeus that gives the impression of swollen ‘‘lips.’’ In some circles today, it is cosmetically fashionable to enlarge human lips by injecting them with collagen, an insoluble fibrous protein. Collagen is derived from the Greek kolla, meaning glue. Collagenus is a play on combining ‘‘collagen’’ (in reference to its use to enlarge lips) and ‘‘genus’’ (in reference to this new genus), hence (loosely) the big-lipped genus. The name Collagenus is considered masculine.

Collagenus dasysternus Ratcliffe and Hardy , new species ( Figs. 1–4 View Fig View Fig )

Type Material. Holotype labeled ‘‘Ven: Bolivar, 10 km N Corocito , 18.VI-3. VII.87, S&J Peck, FIT, R. Caura rainforest.’’ Holotype deposited at the Canadian Museum of Nature (Ottawa, Canada) .

Description of Holotype. Male ( Fig. 1 View Fig ). Length from apex of clypeus to apex of elytra 20.1 mm; width at humerus 9.6 mm. Color of dorsum and legs dark reddish brown, color of pygidium and venter reddish brown. Head: Frons with surface densely, coarsely rugopunctate; center with small, transverse, feebly elevated boss. Frontoclypeal carina strong, elevated, complete from side to side, weakly arcuate towards posterior. Clypeus with surface densely, coarsely rugopunctate; apex broadly parabolic, with strongly thickened anterior rim, rim strongly reflexed ( Fig. 2 View Fig ); clypeus greatly swollen ventrally. Mandibles small, subtriangular, slender, completely hidden beneath clypeus. Mentum enlarged and strongly protuberant ventrally. Interocular width equals 5.0 transverse eye diameters. Anterior edge of eye canthus with dense, long, reddish brown setae. Antenna with 10 segments, club subequal in length to segments 2–7. Maxillary palpus with last segment longitudinally depressed and roughened on lateral edge, length 3 times longer than preceding (third) segment, third segment half as long as second segment. Pronotum: Surface entirely punctate; punctures moderate in density, size small (becoming slightly larger in anterior and posterior angles). All margins with strong bead. Sides evenly arcuate. Elytra: Surface between suture and humerus with 1 furrowed sutural stria and 2 pair of furrowed discal striae. Intervals slightly convex, those between striae 1–2 and 4–5 with irregular row of large punctures. Sides laterad of humerus with 4 distinct rows and 2 indistinct rows of punctures. Propygidium: Surface finely alutaceous with moderately dense, small punctures. Pygidium: Surface entirely punctate; punctures moderate in density and size, becoming slightly smaller at apex. In lateral view, surface strongly, evenly convex. Legs: Trochanter and femora with dense, long, yellowish brown setae. Tibiae with moderately dense, long, stout, yellowish brown setae, those on anterior femora mostly on venter. Foretibia tridentate, teeth becoming progressively larger from base to apex; apical tooth slightly removed from others, long, curved; apex of foretibia obliquely truncate. Meso- and metatibiae each with strong, obliquely transverse carina at about middle on lateral edge; apices expanded, each with fringe of long, stout bristles. Tarsi slender, subequal in length to their respective tibiae, each tarsomere at apex with 5–10 long, stout, reddish brown setae. Claws slender, equal in size. Vente r: Thoracic sternites clothed with dense, long, yellowish brown setae. Prosternal process a very small, rounded protuberance. Abdominal sternites shining, glabrous except for about 20 small setae in a transverse row on penultimate segment. Last sternite with apex weakly bisinuate. Parameres: Figs. 3–4.

Etymology. From the Greek roots dasy, meaning shaggy or hairy, and sternon, meaning chest or sternum. So named in reference to the densely setose thoracic sternites, hence dasysternus .

Distribution. Known only from a single specimen collected in a flight intercept trap just north of Corocito, which is south of Ciudad Piar on the west side of Embalse de Guri in Bolivar state, Venezuela. Nothing is known of its biology.

Revised Key to the Genera of New World Pentodontini

1. Antenna with 9 segments - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2

1 9. Antenna with 10 segments - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 3

2(1). Head in both sexes with a short horn. Apical region of pronotum declivous. Argentina - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Eremobothynus Ohaus 1910

2 9. Head lacking horns, instead with a transverse carina. Apical region of pronotum not declivous. SW United States - - - - - - - - - - - Aphonides Rivers 1889

3(1 9). Small species, generally less than 15 mm in length. Head lacking carina, tubercles, or horn (rarely with a trace of tubercles). Pronotum lacking tubercles or fovea. Posterior tibia strongly broadened towards apex - - - - - - - - - 4

3 9. Larger species, generally greater than 15 mm in length. Head with transverse carina (on subapex of clypeus or frontoclypeal suture), tubercles, or horn. Pronotum usually with tubercles (rarely obsolete in Aphonus , Indieraligus , Collagenus , some Tomarus , occasionally Philoscaptus ) and usually with a fovea or sulcus behind tubercles. Posterior tibia not strongly broadened apically - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 7

4(3). Color black - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 5

4 9. Color rufous or reddish yellow - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 6

5(4). Pronotum completely and distinctly punctate. Propygidium lacks stridulatory striae. Southern United States through South America - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Euetheola Bates 1888

5 9. Pronotum virtually impunctate. Propygidium with stridulatory striae. African genus with one species introduced into southern Brazil - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Heteronychus Burmeister 1847

6(4 9). Posterior femur greatly thickened, apex of posterior tibia greatly expanded. Peru - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Pentodina Endrödi 1968

6 9. Posterior femur normal, apex of posterior tibia not greatly expanded. Honduras to Brazil and Peru - - - - - - - - - - - - - - - - - - - Parapucaya (in part) Prell 1934

7(3 9). Size large (30–35 mm). Color rufous. Mandibles without teeth on external margin. Male with central horn on head, pronotum with a strong bifurcate tubercle or horn. Anterior tibia with a small, basal, fourth tooth. Posterior leg with basal tarsomere very wide. Propygidium without stridulatory striae. Argentina, Brazil, Colombia - - - - - - - - - - - - - - - - - - - - - - - - - - Thronistes Burmeister 1847

7 9. Not with above combination of characters - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 8

8(7 9). Clypeal apex acute, unidentate - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9

8 9. Clypeal apex bidentate, truncate, or rounded - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 10

9(8). Mandibles large, tridentate. Southern United States, northern Mexico - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Oxygrylius Casey 1915

9 9. Mandibles smaller, nearly hidden by clypeus, lacking lateral teeth. South America - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Oxyligyrus Arrow 1908

10(8 9). High, transverse carina present immediately behind apex of clypeus - - - - - - 11

10 9. Transverse carina absent immediately behind apex of clypeus - - - - - - - - - - - - - - 12

11(10). Transverse carina (usually tridentate) just behind apex of clypeus. Pronotum without tubercles. Size generally less than 17 mm. United States west of the Rocky Mountains - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Aphonus LeConte 1856

11 9. Transverse carina just behind apex of clypeus entire or bidentate. Pronotum tuberculate or not. Size generally greater than 17 mm. Central and SW United States, Mexico, Guatemala, El Salvador, Nicaragua, Honduras - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Orizabus Fairmaire 1878

12(10 9). Mandibles only slightly visible from above or hidden under clypeus; outer edge arcuate, not toothed or convexly rounded - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 13

12 9. Mandibles distinctly visible from above; outer edge toothed or convexly rounded or lobed - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 17

13(12). Clypeus strongly narrowed toward apex, apex narrowly bidentate. Color castaneous to black. Canada to Chile - - - - - - - Tomarus (in part) Erichson 1847

13 9. Clypeus not strongly narrowed toward apex, apex broadly truncate. Color fulvous to rufocastaneous - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 14

14(13 9). Frontoclypeal suture present, deeply impressed, strongly arcuate either side of middle. Head lacking horns or tubercles. Length 14 mm or less. Honduras to Brazil and Peru - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Parapucaya (in part) Prell 1934

14 9. Frontoclypeal suture absent. Head with horns, tubercles, or low boss. Length 18 mm or greater - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 15

15(14 9). Small horn (males) or tubercle (females) present next to each eye. Apex of pronotum declivous with subapex weakly to strongly bituberculate. Panama, Colombia, Ecuador - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Pucaya Ohaus 1910

15 9. Paired horns or tubercles absent. Center of head with, at most, a low boss. Apex of pronotum evenly convex - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 16

16(15 9). Clypeus with apex strongly emarginate, reflexed, apical rim thin. Center of head slightly tumid. Prosternal process long, columnar. SW United States, N. Mexico - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Coscinocephalus Prell 1936

16 9. Clypeus with apex broadly parabolic, apical rim strongly thickened ( Fig. 2 View Fig ). Center of head with strong, elevated carina, carina complete from side to side. Prosternal process small, rounded. Venezuela - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Collagenus Ratcliffe and Hardy , new genus

17(12 9). Mandibles entire or lobed on lateral edge - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 18

17 9. Mandibles distinctly tridentate (1 apical tooth, 2 lateral teeth) - - - - - - - - - - - - - - - 23

18(17). Apex of clypeus narrowly bidentate. Ecuador (Galapagos Islands) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Neobothynus Prell 1936

18 9. Apex of clypeus truncate, acute, or narrowly rounded - - - - - - - - - - - - - - - - - - - - - - - - - 19

19(18 9). Clypeus abruptly constricted at apex; tip elongate, narrowly truncate or rounded. Males with head horn, pronotum with bifurcate horn; females lacking horns. Color piceous (females) to grey-tomentose (males), opaque. Brazil, Argentina - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Diloboderus Reiche 1859

19 9. Clypeus regularly acuminate, subtriangular. Horns absent. Color castaneous, shining - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 20

20(19 9). Pronotum lacking distinct apical fovea, sulcus, or tubercle or fovea either side of middle; marginal bead absent on base. Scutellum impunctate. Base of pygidium, lateral edge of abdominal sternites and meso- and metatibiae with extremely long, dense setae. Puerto Rico - - - - - Indieraligus Dechambre 1979

20 9. Pronotum with distinct apical fovea, sulcus, or tubercle or fovea either side of middle; marginal bead present on base. Scutellum with punctures. Setae present on meso- and metatibiae, pygidium, or sternites but extremely long setae absent - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 21

21(20 9). Clypeus strongly convex on dorsal surface. Frontoclypeal suture strongly elevated into a transverse, weakly bituberculate ridge. Pronotum with a shallow, ovoid concavity in median half behind subapical tubercle (male) or with subapical rounded swelling (female). Elytron with sutural stria and 3 feebly indicated discal striae. Mexico - - - - - - - - - - - - - - - - Gillaspytes Howden 1980

21 9. Clypeus not strongly convex on dorsal surface, either weakly convex in basal half only or weakly concave. Frontoclypeal suture with a transverse tubercle only. Pronotum lacking a shallow, ovoid concavity in median half behind apical margin, instead a median longitudinal sulcus or a shallow fovea either side of middle. Elytron with sutural stria and 4–5 punctate-striate rows on disc - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 22

22(21 9). Apex of clypeus narrowly truncate. Tubercle on head entire. Pronotum with shallow fovea either side of disc; subapical sulcus and apical tubercles absent. Metasternum setigerously punctate in anterior half only. Paraguay - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Heikeianus Endrödi 1978

22 9. Apex of clypeus narrowly rounded. Tubercle on head feebly emarginate. Pronotum without fovea either side of middle; both sexes with a weak, subapical, longitudinal sulcus (weaker in females), and males with an apical, emarginate tubercle. Metasternum completely, setigerously punctate. Panama, Costa Rica - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Barutus Ratcliffe 1981

23(17 9). Propygidium with stridulatory striae or granules - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 24

23 9. Propygidium lacking stridulatory striae or granules - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 26

24(23). Apical segment of maxillary palpus expanded, triangular. South America - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Hylobothynus Ohaus 1910

24 9. Apical segment of maxillary palpus normal, cylindrical - - - - - - - - - - - - - - - - - - - - - - - 25

25(24 9). Foretibia tridentate. Mexico through South America - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Bothynus Hope 1837

25 9. Foretibia bidentate. Southern Brazil - - - - - - - - - - - - - - - Parabothynus Endrödi 1968

26(23 9). Elytron with sparse, minute punctures, appearing smooth. Clypeus on sides constricted at base. Southern Brazil - - - - - - - - - - - - - - - - - - - - - - - - - - - Aceratus Prell 1936

26 9. Elytron distinctly punctate or punctate-striate. Clypeus not constricted at base - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 27

27(26 9). Body form suboval, stout, strongly convex on dorsum. Surface coarsely punctate-striate. Frontoclypeal carina short, less than 1/3 width of base of clypeus. Pronotum evenly convex or with a trace of an apical tubercle. Argentina, Uruguay, S. Brazil - - - - - - - - - - - - - - - - - - - - - - - - Philoscaptus Bréthes 1919

27 9. Body form more elongate, less stout, not strongly convex on dorsum. Surface variably punctate. Frontoclypeal carina long, interrupted at middle or not or replaced by 2 distinct tubercles. Pronotum with or without apical tubercle and subapical fovea. Canada to Chile - - - - - - - - - - - - Tomarus (in part) Erichson 1847

R

Departamento de Geologia, Universidad de Chile

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Dynastidae

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