Russian J. ThenoL 2 (1): 49-58 © RUSSIAN JOURNAL OF THERIOLOGY, 2003 Cladistic analysis of the dormouse genus Graphiurus Smuts, 1832 (Rodentia: Gliridae), with comments on evolution of its zygomasseteric construction and subgeneric taxonomy Igor Ya. Pavlinov & Elena G. Potapova ABSTRACT. Cladistic analysis of relationships among 10 Graphiurus species based on 30 cranial characters allowed us to recognize three clades Accordingly, Aethoghs (includes G. nagtglasi) and Clavighs (includes G. crassicaudatus) are to be tieated as subgenera. Monophyly of Graphiurus s str. (supposedly including all other species) is formally proved by our analyses but requires future investigation pending on inclusion of more taxa and characters Diagnoses of Aethoghs and Clavighs are provided. A possible scenario for the evolution of zygomasseteric construction mGraphiurus is discussed. It is supposed that primitive hystncomorphy is initial, whereas myomorphy is a derived zygomasseteric feature of this genus. KEY WORDS: Gliridae, Graphiurus, Aethoghs, Clavighs, taxonomy, zygomasseteric construction. Igor Ya Pavlinov [igor_pavlmov@zmmu msu ru], Zoological Museum of Moscow State University, ul Bolshaya Nikitskaya 6, Moscow 103009, Russia, Elena G Potapova, Institute of Ecology and Evolution, Russian Academy of Sciences, Lemnsky prospect 33, Moscow 119071, Russia Кладистический анализ сонь рода Graphiurus Smuts, 1832 (Rodentia: Gliridae), с заметками по эволюции зигомассетерной конструкции и подродовой систематике И.Я.Павлинов, Е.Г.Потапова РЕЗЮМЕ. Кладистический анализ родственных связей между 10 видами Graphiurus по 30 кранио- логическим признакам позволяет различать три клады. На этом основании таксоны Aethoghs (включая G nagtglasi) и Clavighs (включая G. crassicaudatus) следует рассматривать как подроды. Монофилия по RpORaGraphiurus s.str. (предположительно включающего все прочие виды) предвари- тельно подтверждена нашим анализом, но необходимо исследование большего числа признаков и видов. Даны диагнозы подродов Aethoghs и Clavighs Обсуждаются возможные пути эволюции зигомассетерной структуры в роде Graphiurus. Предполагается, что для этого рода исходным состоянием была примитивная гистрикоморфия, а производным — миоморфия. КЛЮЧЕВЫЕ СЛОВА. Gliridae, Graphiurus, Aethoghs, Clavighs, систематика, зигомассетерная конструкция. Introduction ghs) appeared to be monotypical, while Clavighs was treated as including most of the species (Allen, 1939). The above-species taxonomy of the native African Later on, lumping tendency predominated in mam- dormice still remains largely controversial. Formerly, mahan taxonomy; all native African dormice were four genus-group taxa have been erected by different included in the single genus Graphiurus in which only authors. The first was Graphiurus Smuts, 1832 with the two subgenera were recognized, nommotypicalGrap/i- type species G. capensis Smuts, 1832 (now synony- turus s.str. with one species and Clavighs with the mized with G. oculans Smith, 1829). Genus Clavighs remainders (Ellerman et al., 1953; Misonne, 1974). Jentink, 1888 (type species C. crassicaudatus Jentmk, Meanwhile, Rosevear (1969) suggested that G. crassi- 1888) has been offered to separate all other African caudatus and G nagtglasi (formerly G. hueti, see dormice species from Graphiurus s.str. Subsequently, Grubb & Ansell, 1996; Holden, in press) be kept as the genus Gliriscus Thomas et Hinton, 1925 has been members of a separate subgenus (or even genus)Clavighs established for G. platyops Thomas, 1897, and the (which synonymizes Aethoghs with the latter); and to genus Aethoghs Allen, 1936 has been offered for G. unite all other species (possibly save G. oculans) to be nagtglasi Jentink, 1888. Thus, four genera in total have united in the subgenus Gliriscus (see also Holden, been recognized for the African dormice by the middle of 1993, 1996). Contrary to this, it was shown by the XX century, of which two (Graphiurus s.str. andAetho- second author (Potapova, 2001) that Clavighs proper 50 Igor Ya Pavlinov & Elena G Potapova /ТЛ mr Figure 1 Rostral region and palate in Graphiurus murinus (A, D), G nagtglasi (B, E) and G crassicaudatus (C, F) in dorsal (A-C) and ventral (D-F) views (after Potapova, in press, with emendations) Abbreviations fio — mfraorbital foramen mr—massetenc ridge mx — maxillare n — nasale pal — palatmum pi nix — praemaxillare,^ ib — superior (sb) and inferior (ib) branches of the anterior zygomatic root tpo — praeorbital tubercle and Aethoghs differ both from each other and from the was undertaken by the present authors (Potapova, 2001, remainder of graphiurmes by auditory bullar mor- in press, Rossohmo et al, 2001), but without explicit phology, a conclusion later supported in part by study phylogenetic argumentation of zygomassetenc morphology (Rossohmoe/ al ,2001) In this paper, we intend to provide phylogenetic Respectively, it was suggested to recognize them as bases for subgenenc classification of the genus Graph- different monotypical subgenera, all other species be- iurus using formal cladistic analysis Special attention ing included in the nommotypical subgenus Graphiu- will be paid to evolution of zygomassetenc construction rus s str (Rossohmo et al, 2001) which is one of the key characters in ghnd phylogeny Nearly all the above concepts of graphiurme taxon- and classification As the morphological background of omy were based on combinatorial (that is, basically the present analysis has been published elsewhere typological) analysis of few skull traits For instance, (Potapova, 2001, in press, Rossohmo et al, 2001), we monotypy of Graphiurus s str was substantiated by do not give any detailed descriptions here The results reduction of upper premolar in G oculans, subgenenc provided herein are to be considered preliminary, as not status of Ghnscus — by flatness of the skull in G all the Graphiurus species was studied by us platyops, separateness of Aethoghs and Clavighs, as well as their unity, was based originally on several Materials and methods quantitative skull characters of respective type species More comprehensive analysis of skull morphology, The following ten species of Graphiurus were studied including zygomassetenc construction and mastoid G angolensis de Winton, 1897, G chnstyi Dollman, 1914, Cladistic analysis of Graphiurus 51 mr mr Figure 2 Rostral region m Graphiurus murmus (A, B), G nagtglasi (C, D), G crassicaudatus (E, F) m lateral (А, С, Е) and frontal (B, D, F) views (after Potapova, m press, with emendations) Abbreviations fw — mfraorbital foramen, m — posterior edge of mcisor.w/ —massetenc ridge, n — па8а1е,лЬ, ib — superior (лb) and inferior (ib) branches of the anterior zygomatlc root, tpo — praeorbltal tubercle, za — zygomatic arch, zp — zygomatic plate G crassicaudatus Jentmk, 1888, G kellem Reuvens, 1890, ters were estimated by visual examination of the specimens, G lorrameus Dollman, 1910, G murmus Desmarest, 1822, while quantitative measurements have been taken by cahper G parvus True, 1839, G nagtglasi Jentmk, 1988, G ocu- and categorized afterward Character descriptions are given laris Smith, 1829, G surdus Dollman, 1912 Additionally, in Appendix 2, the data matrix is given in Tab 1 the following rodent species were included in the sample Parsimony cladistic analysis was conducted with PAUP studied to make the similarity relations among graphiunnes 311 (Swofford, 1993) The characters in different runs were by some morphological structures more evident Spermophi- included in either unordered or irreversible (some of them, lus sp , Ghs ghs Linnaeus, 1766 andDryomys lamgerFelten see Results and discussion section) modes, all equally weight- & Storch, 1968 The specimens examined (see Appendix 1) ed Branch-and-bound algorithm was employed for search- belong to collections of the American Museum of National ing initial minimum-length trees and 50% majority-rule History (AMNH), Museum National d'Histoire Naturelle consensus tree was calculated for each branch-and-bound (MNHN), and Zoological Museum of Moscow University run Additionally, bootstrapping (with 100 replicates) was (ZMMU) used to assess support of tree topologies In all runs, the trees Thirty morphological traits used in cladistic analysis to were rooted by an artificial outgroup m which character represent the following skull portions rostrum, zygomasse- states were defined by one of us (EP), taking into consider- tenc construction (Figs 1 and 2), bramcase, palate, denti- ation most probable evolutionary scenarios for respective tion, mandible, auditory bulla (Fig 3) Quantitative charac- characters in sciurognath rodents 52 Igor Ya. Pavlmov & Elena G. Potapova um um aac sea ac Figure 3. External (A, D, G) and internal (В, Е, H) mastoid morphology and scheme of the tympanic cavity expansion into mastoid (C, F, I) in Graphiurus nagtglasi (A-C), G. crassicaudatus (D-F), G. lorrameus (G), G. murmus (H, I) in lateral and slightly dorsal view. The lateral outer wall removed in B, E, and H. Arrows in C, I, and F indicate direction of the tympanic cavity expansion. The septae between the chambers as well as the anterior, dorsal and posterior outer walls of the mastoid are shaded. After Rossolimo at al. (2001), with emendations. Abbreviations ac—antral chamber, aac—additional antral chamber, ec — epitympanic chamber, emc — epitympano-mastoid chamberjmj — foramen for stapedius muscle, fst—stylomastold foramen, imc — inferior mastoid chamber, Ip — lateral pocket,pZ? — parafloccular bulge, sc— semicircular canals anterior (sea), lateral (scl), posterior