Platycerus

Huang, Hao & Chen, Chang-Chin, 2009, Notes on the morphology, taxonomy, and natural history of the genus Platycerus Geoffroy from China, with the description of a new species (Coleoptera: Scarabaeoidea: Lucanidae), Zootaxa 2087, pp. 1-36 : 29-31

Key to males of Chinese species and subspecies of Platycerus

All species of Platycerus are strongly sexual dimorphic and males can be easily distinguished from females, thus males and females are included into the separate keys. In males of all known species, the metatarsi are longer than metatibia, the head is wider than half of the elytra, the mandible is longer than half of the head, and each mandible bears two basal molae behind the incisor teeth. Whereas in females of all known species, the metatarsi are markedly shorter than metatibia, the head is half as wide as elytra, the mandible is shorter than half of the head, and each mandible bears no mola at base. Moreover, the females of Platycerus species usually have the anterior margin of the head less concave, antennomere 7 less lamellate, antenna shorter with antennomeres 7-10 occupying a smaller proportion in length, body stouter and thicker, and terminal spines on protibia markedly longer than in males.

No work has been done on the phylogeny of Platycerus . Therefore, the order of branching in the following key is not in accordance with natural groups. The authors preferentially use the external diagnostic characters than to use the genital characters in the key. In the following key, Platycerus kitawakii and Platycerus turnai are placed in distant couplets; however the authors believe these two species might be very close in phylogeny as they share some peculiar characters in the keel of the penis and the endophallus.

1 All femora more or less with some part shiney red or shiney brown ........................................................................... 3

- All femora entirely black .............................................................................................................. 2 ( Platycerus hiurai )

2 Dorsal color less green. Anterior angle of pronotum less protruded. Transverse wrinkles on elytra broadly distributed.......................................................................................................................................... Platycerus hiurai hiurai

- Dorsal color more green. Anterior angle of pronotum more protruded. Transverse wrinkles on elytra narrowly distributed ............................................................................................................................... Platycerus hiurai tanikadoi

3 Metasternum entirely bright reddish brown.................................................................................................................. 4

- Metasternum black or blue, at most with a small part bright brown ............................................................................ 7

4 All tibiae darker, black or blackish brown on dorsal surface. Left mandible with at least four blunt incisor teeth; the gap between apex and incisor teeth smaller; the distance between incisor teeth and mola longer. Paramere not remarkably bulged on lateral surface near base. Lateral keel of penis obsolete at lateral half .................................... 5

- All tibiae brighter and red on dorsal surface. Left mandible with three blunt incisor teeth; the gap between apex and incisor teeth greater; the distance between incisor teeth and mola shorter. Paramere remarkably bulged on lateral surface near base. Lateral keel of penis broader at lateral half......................................................... Platycerus feminatus

5 Dorsal surface with a brown tinge. Mandible with a smaller concave area on dorsal surface. Pronotum with anterior part of lateral margins more convergent ................................................................................ Platycerus cupreimicans

- Dorsal surface without a brown tinge. Mandible with a larger concave area on dorsal surface. Pronotum with anterior part of lateral margins less convergent ................................................................................. 6 ( Platycerus dundai )

6 Elytra relatively longer. Dorsal surface bluish green............................................................ Platycerus dundai dundai

- Elytra relatively shorter. Dorsal surface yellowish green ................................................ Platycerus dundai miyatakei

7 Posterior angle of pronotum angled............................................................................................................................. 8

- Posterior angle of pronotum rounded ......................................................................................................................... 16

8 Mandible with a gap between apex and incisor teeth, and with a conjoined inner margin of incisor teeth .............. 10

- Mandible without a gap between apex and incisor teeth, and each with a single incisor tooth ................................... 9

9 Dorsal color brown. Middle and hind legs with tarsi as long as tibia. Abdominal sternites bright reddish brown. Distance between incisor teeth and mola of mandible shorter. Keel of penis narrower at basal half. Flagellum not bifurcate at base. Lateral inflations alongside flagellum on endophallus elongated and protruded basad as free branches. .......................................................................................................................................................... Platycerus yingqii

- Dorsal color green. Middle and hind legs with tarsi markedly longer than tibia. Abdominal sternites dark black. Distance between incisor teeth and mola of mandible longer. Keel of penis broader at basal half. Flagellum bifurcate at base. Lateral inflations alongside flagellum on endophallus broad and not protruded as free branches ....................... ........................................................................................................................................................ Platycerus rugosus

10 Conjoined inner margin of incisor teeth on left mandible more or less with a cleft in middle. Basal piece of male genitalia with dorsal sclerites peaked at tip. Penis narrower in ventral view. Paramere slightly bulged at base............ .................................................................................................................................................. 11 ( Platycerus tabanai )

- Conjoined inner margin of incisor teeth on left mandible smooth and evenly curved. Basal piece with dorsal sclerites broadly rounded at tip. Penis wider in ventral view. Paramere strongly bulged at base................................................. .........................................................................................................................................13 ( Platycerus hongwonpyoi )

11 Dorsal color more blue. Anterior angle of pronotum a little blunt........................... Platycerus tabanai baotianmanus

- Dorsal color less blue. Anterior angle of pronotum sharper....................................................................................... 12

12 Conjoined inner margin of incisor teeth of both mandibles dentate. Eye smaller ............. Platycerus tabanai tabanai

- Conjoined inner margin of incisor teeth of both mandibles smooth except for a shallow cleft on left mandible. Eye larger ..................................................................................................................... Platycerus tabanai taibaishanensis

13 Dorsal color basically blue ........................................................................................................................................ 14

- Dorsal color basically green ....................................................................................................................................... 15

14 Protibia more or less brown ............................................................................... Platycerus hongwonpyoi mongolicus

- Protibia entirely black................................. Platycerus hongwonpyoi hongwonpyoi , Platycerus hongwonpyoi merkli

15 Transverse wrinkles on elytra deeper, denser and broadly distributed ........................................................................... Platycerus hongwonpyoi qinlingensis , Platycerus hongwonpyoi dabashanensis , Platycerus hongwonpyoi funiuensis , Platycerus hongwonpyoi shennongjianus

- Transverse wrinkles on elytra shallower, sparser and narrowly distributed ... Platycerus hongwonpyoi tianmushanus

16 Lateral margin of mandible convex, straight, or slightly concave. Metasternum entirely dark ............................... 17

- Lateral margin of mandible conspicuously concave. Metasternum with posterior part shiney brown .......................... .......................................................................................................................................................... Platycerus ladyae

17 Keel situated at distal end of sclerotized penis ........................................................................................................... 18

- Keel situated at central part of sclerotized penis, or obsolete as a ridge along lateral margin, but never at distal end of penis ........................................................................................................................................................................... 19

18 Mandible with a large concave area on dorsal surface, lateral margin straight or slightly concave, apex sharp, with at least six incisor teeth. Sclerotized part of penis not wider than paramere .................................... Platycerus kitawakii

- Mandible without concave area on dorsal surface, lateral margin slightly convex, apex blunt, with no more than five incisor teeth. Sclerotized part of penis wider than paramere ............................................................. Platycerus turnai

19 Distance between incisor teeth and molae longer than or subequal to the conjoined inner margin of molae. Keel of penis broader near middle than at all other parts, somewhat even in width throughout or reduced as a lateral ridge ... .................................................................................................................................................................................... 20

- Distance between incisor teeth and molae shorter than the conjoined inner margin of molae. Keel of penis broader at basal part and narrower at distal part .......................................................................................................................... 24

20 Incisor teeth at least six in number, with the conjoined inner margin much longer than half the length of the whole mandible........................................................................................................................................ Platycerus businskyi

- Incisor teeth at most five in number, with the conjoined inner margin not longer than half the length of the whole mandible..................................................................................................................................................................... 21

21 Dorsal color coppery brown ........................................................................................................ Platycerus nagahatai

- Dorsal color basically green ....................................................................................................................................... 22

22 Dorsal color more blue. Transverse wrinkles on elytra broadly distributed................................. Platycerus consimilis

- Dorsal color less blue. Transverse wrinkles on elytra narrowly distributed............................................................... 23

23 Endophallus with three pairs of inflations alongside and behind flagellum....................................... Platycerus yeren

- Endophallus different or unknown at present ................... Platycerus bashanicus , Platycerus consimilis phagophilus

24 Anterior angle of pronotum more protruded into an acute angle. Endophallus with lateral inflations not protruded as free branches and with flagellum shorter ............................................................................................. Platycerus tangi

- Anterior angle of pronotum less protruded and blunt at tip. Endophallus with lateral inflations protruded as free branches and with flagellum longer ............................................................................................................................ 25

25 Transverse wrinkles on elytra shallower and narrowly distributed. Mandibles evenly curved on outer lateral margin ...................................................................................................................................................... Platycerus tieguanzi

- Transverse wrinkles on elytra deeper and broadly distributed. Mandibles angled on outer lateral margin ................... .............................................................................................................................................. Platycerus cyanidraconis