Nature 315, 140 - 141 (09 May 1985); doi:10.1038/315140a0

Evidence for echolocation in the oldest known bats

Michael J. Novacek

Department of Vertebrate Paleontology, American Museum of Natural History, New York, New York 10024, USA

The earliest-known bats are represented by excellent fossil material, including virtually complete skeletons of Icaronycteris index from the early Eocene (50 Myr BP) of western Wyoming^1,2 and Palaeochiropteryx tupaiodon from the middle Eocene (45 Myr BP) 'Grube Messel' of western Germany^3,4. These taxa have been closely allied^1,5 with Recent Microchiroptera, a suborder of diverse bats noted for their powers of ultrasonic echolocation⁶. A problem with this relationship is the alleged absence in the Eocene forms of specializations in the auditory region⁷ and other aspects of the skeletal system^1,2. It has been proposed, therefore, that the oldest bats are members of a group more primitive and possibly ancestral to the Microchiroptera and the visually oriented Megachiroptera⁸. Previously undescribed specimens now show, however, that Icaronycteris (Fig. 1) and Palaeochiropteryx (Fig. 2) share special basicranial features with microchiropterans which suggest comparable refinement of ultrasonic echolocation. These results support the theory that a sophisticated sonar system was present in the earliest records of microchiropteran history.

References

1.	Jepsen, G. L. Science 154, 1333−1339 (1966). | ISI |
2.	Jepsen, G. L. in Biology of Bats Vol. 1 (ed. Wimsatt, W. A.) 1−64 (Academic, New York, 1970).
3.	Revilliod, P. Abh. hess. geol. Landesanst. 7, 157−201 (1917).
4.	Richter, G. & Storch, G. Natur. Mus., Frankf. 110, 353−367 (1980).
5.	Smith, J. D. & Storch, G. Senckenberg. biol. 61, 153−167 (1981).
6.	Koopman, K. F. in Orders and Families of Recent Mammals of the World (eds Anderson, S. & Jones, J. K.) 145−186 (Wiley, New York, 1984).
7.	Segal, W. Fieldiana, Zool. 58, 103−108 (1971).
8.	Van Valen, L. Evol. Theory 4, 103−121 (1979).
9.	Stanek, V. J. Nakladen Ceske Akad Ved a Umeni, 1−67 (V. Praze, 1933).
10.	Henson, O. W. Kans. Univ. Sci. Bull. 42, 151−255 (1961).
11.	Tepaske, E. R. thesis, Oklahoma State Univ. (1964).
12.	Fleischer, G. Säugetierk. Mitt. 21, 131−239 (1973).
13.	Fleischer, G. Evolutionary Principles of the Mammalian Middle Ear (Springer, Berlin, 1978).
14.	Henson, O. W. in Biology of Bats Vol. 2 (ed. Wimsatt, W. A.), 181−261 (Academic, New York, 1970).
15.	Novacek, M. J. Proc. 5th int. Bat Res. Conf., 317−330 (Texas Technical Press, Lubbock, 1980).
16.	Sprague, J. M. Am. J. Anat. 72, 385−472 (1943).
17.	Griffiths, T. A. Mammalia 47, 377−394 (1983). | ISI |
18.	Pye, A. J. Morph. 119, 101−120 (1966). | PubMed | ISI | ChemPort |
19.	Bruns, V. Verh. dt. zool. Ges. 141−154 (1979).
20.	Bruns, V., Fiedler, J. & Kraus, H. J. Myotis Vols 21−22 (1983−1984).
21.	van der Klaauw, C. J. Bull. Am. Mus. nat. Hist. 62, 1−352 (1931).
22.	Suthers, R. A. & Fattu, J. M. Am. Zool: 13, 1215−1226 (1973). | ISI |
23.	von Bekesy, G. Experiments in Hearing (McGraw-Hill, New York, 1960).
24.	Dallos, P. The Auditory Periphery (Academic, New York, 1960).
25.	Harris, D. M. & Dallos, P. Science 225, 741−743 (1984). | PubMed | ISI | ChemPort |
26.	Novacek, M. J. Proc. 1st int. Congr. Vert. Morphol. (Fischer, Stuttgart, in the press.)
27.	Simmons, J. A., Howell, D. J. & Suga, N. Am. Sci. 63, 204−215 (1975). | PubMed | ISI | ChemPort |
28.	Fenton, M. B. Q. Rev. Biol. 59, 33−53 (1984). | Article | ISI |