First Record of the Genus Megaderma Gpot .Roy (Microchiroptera
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FIRST RECORD OF THE GENUS MEGADERMA GPOT.ROY (MICROCHIROPTERA : MEGADERMATIDAE) FROM AUSTRALIA by SuzanneHAND * CONTENTS Page Abstract,Rdsum6 48 Introduction 48 Systematics 49 Comparisons with other megadermatids . 53 Fossil forms 53 Living taxa. 55 Phylogeneticrelationships 57 Discussion 58 Assignment to M egaderma 58 Intrageneric relationships 60 Palaeobiogeographyand palaeoecology . 61 Acknowledgements 62 References 63 Appendix. .. 65 Legendsofplates 66 * School of Biological Science,University of New South Wales,PO Box l, Kensington,Sydney, NSW 2033, Australia Key-words: Chiroptera, Megaderma, Megadermatidae, Pliocene, Rackham's Roost Site, Riversleigh, Australia. Mots-cl6s: Chiroptera, Megaderma, Megadermatidae,PliocEne, Localit6 Rackham's Roost, Riversleigh, Australie. Paheovertebrara, Montpellier,24 (l-2): 4146,2 pl. (Regule 29Juillet 1993, acceptd le 23 Septembre1993, publi€ le 14Juin 1995) ABSTRACT A new Tertiary megadermatid is described from Rackham's Roost Site, a Pliocene limestone cave deposit on Riverileigh Station, northwestern Queensland, Australia. It appears to represent the first Australian record of Megaderma GeoFrnoy, 1810, a genus otherwise known from Tertiary African and (Lyroderma) European taxa and the living Asian species M. spasma (Lu'rNeeus,1758) and M- lyra perens, 1872. Megaderma richardsi n. sp. is one of the smallest megadermatids known. It exhibits a mixture of plesiomorphic and autapomorphic features, the latter appearing to exclude it from being from the ancestralto any living megadermatid.The new speciesis one of eight megadermatidsidentified Australian fossil record, most of which are referable to Macroderma Mtu-en, 1906' RESUME gisement Un nouveau mdgadermatid6 tertiaire est ddcrit de la localit6 Rackham's Roost, un premidre cavernicolepliocbne de RiversleighStation, Nord-Ouest Queensland, Australie' Il repr6sentela jusqu'ici decouverteaustralienne du Megaderma GeorrRov, 1810, un genre connu par des espdces et tertiairesafricaines et europdenneset par les espbcesrdcentes asiatiques M. spasma(LnNneus, 1758) M. (Lyroderma.) /yra Prrrns , 1872. Megaderma richardsi n. sp. est un des plus petits m6gadermatid6s de toute connus.Il montre un mdlangede pl6siomorphieset d'autapomorphies,ces dernibresI'excluant ascendanceh l'6gard des m6gadermatid6srdcents. L'espEce nouvelle est I'un des huit m6gadermatid6s 1906. d6nombr6sdans le r6gistre fossil australien,dont la plupart sont r6f6rablesde MacrodermaMtrt-ex, INTRODUCTION The bar family Megadermatidaeis an Old World tropicalgroYp Yltll five extant species.These are iommonly (e.g.Honacki et aI. 1982,Hill & Smith 1984)referred to fiur genera.Three genera,Lavia GRAY,1938, CardiodermaPETERS, 1873 and Macridermc MTLLER,1906, are consideredto be monotypic.Megaderma GEOFFROY, 1810then containstwo species,Megaderma spasrna Md M. (Lyroderma)Iyra. I-avia alrdM' spasmaNe frons andCardioderma cor Ne African species,Megaderma lyra Asian andMacroderma glgas Australian. Megadermatidsare insectivorous(e.g. L. fron! or facultativelycarniv.orous and are gene;lly characterisedby a dentitionadapted for meat-eating.The fanlly is well reprEsentedin the fossil record,being known from at least 19 fossil taxa from early fertiary to Quaternarysediments in Europe,Africa andAustralia (e.g. Sig6 1976;Hand 1985,iable 8; Sevilla 1990;Ziegler1993). The majority of Tertiarymegadennatids are referred to the genus Megadirmd, a notable exception being the oldest known megadermatid,I{ecromantii adichasterWetrsoreR, 1887 from late EoceneFrench sediments(Remy et aI.1987). In lgi6, Sig6 examined the evolutionary history of megadermatidsand recommendedrecolnition of only threemegadermatid genera, Necromantis, Invia and Megaderma,the latter containingCardioderma and Macrodermaas subgenera'He 48 arguedthat, without rarely preservedcranial material, fossil megadermatidscould not be confidently assignedto the more restrictedspecies groups commonly used for living taxa. Subsequently,however, after examination of new Australian fossil megadermatid material, Hand (1985) suggestedthat the generic narte Macroderma be retained for an Australian clade which now includes at least three Tertiary species (M. godthelpi HAND,1985, M. koppa HeNp et al., 1988 and M. malugarc HAND,submitted) as well as Australia'sonly living megadermatidM. gigas (DonsoN, 1880).She also suggested that the name Lyroderma might be resurrectedfor M. Iyra and the middle Miocene M. gaillardi (Tnourssanr, I 898). Although most Australian Tertiary megadermatids appear referable to Macrodermc, Miocene depositson RiversleighStation, northwestern Queensland, have also produced enigmatic taxa such as the Dwornamor Variant (Hand 1985) and the Henk's Hollow megadermatid indet. (Hand submitted) that lack apparent synapomorphiesfor this clade. Thesetaxa are representedby isolatedteeth and cannot be confidently assignedto any other speciesgroup. A tiny, new megadermatidfrom Riversleigh'sPliocene Rackham's Roost Site (Hand 1987,Archer et al. 1989,1991) is possiblyallied to theseMiocene forms but is betterrepresented, by a maxillary fragment and severalisolated teeth,and is tentativelydescribed here as the first representativeof the genusMegaderma from Australia. Dental terminology follows Hand (1985). The prefix QM F- indicatesthat the sourceof specimensis the QueenslandMuseum fossil collection. SYSTEMATICS OTdeTCHIROPTERA BLUMENB ^CH, I7 79 SuborderMICROCHIROPTERA DossoN, 1875 Superfamily RHINoLoPHoIDEA Gnev, 1825 Family MEGADERMATTDAEAt-t-EN, 1 864 GenusMEGADERMA GEOTTNOY, 1810 Megaderma richardsi n. sp. (Pr.1-2) Holotype: QueenslandMuseum F236L9,a right maxillary fragmentwith Cr and Pa. Etymology: The speciesis named after Greg Richards, one of Australia's foremost bat researchers,whose help in interpreting aspects of Riversleigh's complex fossil bat faunasis greatly appreciated. Paratypes (from type locality): QM F23620,a right C'; QM F23621,a left Ct. Referred material (from type locality): QM F23598, a right M'; QM F23599,a right tvlt; QM F23600, a left M '. Type locality, lithology and age: The type locality, Rackham'sRoost Site (Godthelp 1988,Archer et al. 1989,1991), occurs at 19.02.09N, 138.41.60E (GlobalPositioning 49 Satellite Device) on Riversleigh Station, northwestern Queensland, and has been described by Hand (submitted). It appearsto represent the indurated floor of a long, narrow cave developed in Cambrian Thorntonia Limestone. At one end, the cave evidently opened onto a vertical cliff flanking what is now the Gregory River. More than 50 metres away in the oppositedirection, another larger, lower opening appearsto have been developed. The sedimentis a breccia of tiny, mostly fragmented bones and teeth set in a fine-grained, pink-coloured (presumably iron-stained) limestone. The deposit covers an area of approximately 2N squaremetres, with a maximum depth of 0.5 to 1.0metre. On the basis of its mammal fauna, the Rackham'sRoost deposit is interpreted to be Pliocenein age.It containsabundant plesiomorphic murids (at least 13 species)and a macropodid similar to Protemnodon snewini BeRntoLovel, 1978 from the early PlioceneBluff Downs Local Faunaof northeasternQueensland (Archer & Wade 1976). Associatedfauna and taphonomy: The Rackham'sRoost depositcontains the remains of crustaceans, fish, frogs, lizards, small crocodileS, Snakes, birds, dasyurids, peramelids,a pseudocheirid,an extinct macropodidand potoroid, at least 13 murids, iwo emballonurids (Taphozousspp), four hipposiderids,four vespertilionids and the large megadermatidMacroderma gigas (Archer et al. 1991, Hand submitted). The very finely broken remains of the small vertebrates and depressed fractures and impressions in the bones characteristicof Recent Macroderma gigas canines suggest thit the deposit representsthe remains of prey accumulatedby that species. Boids, the emballonuiids, hipposiderids and vespertilionids probably cohabited the megadermatid roost;the macropodidmay havecamped near the cave'sentrance. Diagnosis: Megaderma richardsi differs from living species of Megaderma (r.e. M. spasmaand M. lyra) in its lossof P2. It differs from most speciesof Megadermain its very smallsize. However, it is similarin sizeto the TertiaryM. iaegeri andM. Iopezae. Megaderma richardsi differs ftom M. jaegeri Srcri, 1976 of the middle Miocene geni Mefal deposit in Morocco in, among other features,its slightly smaller size, Cr with taller anterior accessorycusp, taller posterior accessorycusp less separatedfrom the main cusp, Mt with shorter postmetacrista,smaller parastyle, less lingually displaced mesostyle, posteriorly opening protofossa, M 1 lower crowned with less sinuous buccal cingulum, trigonid and talonid subequal in length, more anteriorly extendedpre-entocristid, and smaller and less posteriorly displacedhypoconulid so that there is little inflexion in the hypocristid. Megaderma richardsi differs from M. lopezae SpvtLLR, 1990 of the late Oligocene Carrascosadel Campo locality, Spain, in its Mt with more lingually displaced mesostyle,posteriorly openingprotofossa, and more posteriorly directed heel, and M t having a more laterally compressedtrigonid, less sinuous buccal cingulum, anteriorly extendedpre-entocristid, the metaconidcontribution to the cristid obliqua less reduced,ana tne nypoconulidless well-developed and lessposteriorly-situated so that it is less distinct from the entoconid and there is little inflexion in the hypocristid. 50 Description The right maxillary fragmentretains Ct and Pa.There is no sign of an alveolusfor P2 either in the tooth row or