Cranial shape variation and phylogenetic relationships of extinct and extant Old World leaf-nosed bats

Abstract

Wilson, L.A.B., Hand, S.J., López-Aguirre, C., Archer, M., Black, K.H., Beck, R.M.D., Armstrong, K.N. & Wroe, S., July 2016. Cranial shape variation and phylogenetic relationships of extinct and extant Old World leaf-nosed bats. Alcheringa 40, 509–524. ISSN 0311-5518

The leaf-nosed bats in Hipposideridae and Rhinonycteridae currently have an Old World tropical to subtropical distribution, with a fossil record extending back to the middle Eocene of Europe. The Riversleigh World Heritage fossil site in northwestern Queensland constitutes a particularly rich archive of faunal diversity for Old World leaf-nosed bats, having yielded more than 20 species. We used 2D geometric morphometrics to quantify cranial shape in hipposiderids and rhinonycterids, with the aim of referring unallocated fossil species, particularly from Riversleigh, to each family within a phylogenetic framework, and using a quantitative approach to reconstruct cranial shape for key clades in these Old World radiations. Our sample comprised 21 extant hipposiderids and rhinonycterids, 1 megadermatid and 1 rhinolophid, in which 31 landmarks were placed in lateral and ventral views, and five measurements were taken in dorsal view. The phylogeny used as the framework for this study was based on an analysis of 64 discrete morphological characters from the dentition, cranium and postcranium scored for 42 extant and fossil hipposiderids and rhinonycterids and five outgroup taxa (rhinolophids and megadermatids). The phylogenetic analysis was conducted using maximum parsimony, with relationships among selected extant taxa constrained to match the results of recent comprehensive molecular studies. Our phylogenetic results suggest that the Riversleigh leaf-nosed bats probably do not represent an endemic Australian radiation, with fossil species spread throughout the tree and several with sister-group relationships with non-Australian taxa. Discriminant analyses (DA) conducted separately on each dataset resulted in cross-validated classification success ranging from 61.9% for ventral landmarks to 71.4% for lateral landmarks. Classification of the original grouped cases resulted in success of 81% for each dataset. Of the eight fossil taxa included as unknowns in the DA, six were found to be assigned to the same group as recovered by the phylogenetic analysis. From our results, we assign the Riversleigh Miocene species Archerops annectens, Brachipposideros watsoni, Brevipalatus mcculloughi, Rhinonicteris tedfordi and Xenorhinos halli to Rhinonycteridae, and Riversleigha williamsi and Hipposideros bernardsigei to Hipposideridae. Our results support Pseudorhinolophus bouziguensis, from the early Miocene of Bouzigues in southern France, as belonging to Hipposideridae, and probably Hipposideros. The reconstructed ancestor of hipposiderids was distinguished from that of the rhinonycterids by having a shorter rostrum, and less of a distinction between the rostrum and braincase.

Laura A.B. Wilson [[email protected]], Suzanne J. Hand [[email protected]], Camilo López-Aguirre [[email protected]], Michael Archer [[email protected]] and Karen H. Black [[email protected]], PANGEA Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, NSW 2052; Robin M.D. Beck [[email protected]], School of Environmental & Life Sciences, University of Salford, Salford M5 4WT, UK; Kyle N. Armstrong* [[email protected]], Department of Genetics and Evolution, School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia. *Also affiliated with South Australian Museum, North Terrace, Adelaide, SA 5000, Australia; Stephen Wroe [[email protected]], School of Environmental and Rural Science, University of New England, Armidale NSW 2351, Australia.

Key words:

• Riversleigh
• systematics
• Hipposideridae
• Rhinonycteridae
• geometric morphometrics

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplemental material

Supplementary File S1: Detailed classification results from the DAs conducted on the following data sets: dorsal measurements, lateral landmarks, ventral landmarks.

Supplementary File S2: Data matrix for PAUP analysis. Available to download from Figshare as a nexus file. DOI: 10.6084/m9.figshare.3190114

Supplementary File S3: Characters and states used in the phylogenetic analysis of rhinolophoid taxa. Available to download from Figshare as a nexus file. DOI: 10.6084/m9.figshare.3190117

Acknowledgements

For access to specimens, we thank R. Portela Miguez and P. Jenkins (NHM London); L. Gordon (USNM), T. Ennis and S. Ingleby (AM); H. Felten and R. Rabenstein (SMF); B. Sigé (UM), N.B. Simmons and E. Westwig (AMNH); H. Janetski (QM); and K.J. Travouillon (WAM). We thank T. Myers and A. Gillespie (UNSW) for skilled preparation of bat skulls collected at Riversleigh. L.A.B.W. is supported by the Australian Research Council (ARC) Discovery Program (DE150100862). C.L.A. is supported by the COLFUTURO scholarship program. Riversleigh fossil research is supported by ARC DP130100197, LP100200486 and DE130100467 grants to S.J.H, M.A. and K.H.B, and R.M.D.B. by ARC DE120100957. We thank P. Creaser and the CREATE Fund at UNSW; the Queensland Parks and Wildlife Service; Riversleigh Society Inc.; Environment Australia; Outback at Isa; and private supporters including K. & M. Pettit, E. Clark, M. Beavis, M. Dickson, S. Lavarack and the Rackham family. Vital assistance in the field has come from many hundreds of volunteers as well as staff and students of UNSW.