19 May 1987 PROC. BIOL. SOC. WASH. 100{2), 1987, pp. 353-357 FOSSIL EVIDENCE OF A TAPACULO IN THE QUATERNARY OF CUBA (AVES: PASSERIFORMES: SCYTALOPODIDAE)

Storrs L. Olson and Evgeny N. Kurochkin

Abstract. -Two bones from Quaternary cave deposits in the Isle of Pines and Camagiiey Province, Cuba, are from a small species of tapaculo (Scytalo- podidae = auct.) that was similar in size and morphology to modem species of . This is the only record of the family outside of , Panama, and Costa Rica, and the only record of the entire superfamily Fur- narioidea in the West Indies. It presents a great zoogeographical anomaly because the species oí Scytalopus are nearly flightless and appear to have little capability for dispersal over water.

When Olson was confronted with a hu- Order Passeriformes Linnaeus, 1758 mérus from cave deposits on the Isle of Pines Superfamily Fumarioidea Ames, 1971 (Isla de Juventud) that seemingly could have Family Scytalopodidae Müller, 1846 come from nothing other than a species of IScytalopus sp. Scytalopodidae (=Rhinocryptidae auct., but Fig. 1 see Brodkorb 1978:147, Feduccia and Ol- son 1982:3), he set the specimen aside in Material examined. • Paleontological disbelief Some five years later, Kurochkin collections of the National Museum of Nat- visited the Smithsonian Institution and ural History, Smithsonian Institution, brought with him a tibiotarsus from a cave USNM 336505, proximal half of right hu- in Camagiiey Province, Cuba, that he had mérus (proximal width, 3.9 mm). Caballos at first tentatively identified as belonging to Mountains, Isle of Pines, Cuba. This spec- the Fumariidae, a related family also un- imen (Fig. la, c) was part of a fairly large known in the Antilles. Recalling the hu- lot of and mammal remains found mérus from the Isle of Pines, Olson sug- among the collections of West Indian cave gested that the tibiotarsus be compared with fossils in the Department of Paleobiology, the Scytalopodidae, with the result that it National Museum of Natural History, was found to match the corresponding ele- Smithsonian Institution. These bore only ment of Scytalopus very closely. The im- locality data and as yet we know nothing probable reality of an Antillean tapaculo be- more concerning their acquisition, although came too difficult to deny any longer. Here they were almost certainly obtained during we present our evidence for the occurrence the first three decades of this century, when of the South America family Scytalopodi- Gerrit Miller was actively studying West In- dae in a zoogeographical subregion where dian cave fossils. no member of the superfamily Fumarioidea Institute of Geology and Paleontology of has hitherto ever been recorded, either liv- the Academy of Sciences of Cuba, IGP 406- ing or fossil. 39, proximal third of left tibiotarsus (prox- PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON 354 imal width through cnemial crest, 4.1 mm; in palmar view (Fig. Ic), It is virtually iden- proximal depth, 3.0 mm) (Fig. le). Collect- tical to the humérus in Scytalopus, the only ed at "Cueva de Los Fósiles," 28.5 km NE differences noted being that in ventral view of Camagüey, Camagüey Province, Cuba, the ventral tubercle is more pronounced and by E. N. Kurochkin and B. W. Woloszyn. the edge of the bicipital crest runs slightly This locality has previously been men- more perpendicular to the shaft. These dif- tioned by Olson (1985a). ferences would probably not prove to be of Age of the localities.•'Nothing is known generic value if sufficient comparative ma- of the exact age of the humérus from the terial of the various species of Scytalopus Isle of Pines, However, no cave deposits were available. have been found anywhere in the West In- The fossil tibiotarsus from Camagüey dies that are known to be older than late agrees with that in the Scytalopodidae in Pleistocene and all are assumed to be Qua- having the proximal end distinctly offset ternary. The specimen appears to be un- medially from the midline of the shaft and mineralized and the collections associated in having a distinct proximally situated crest with it contained an abundance of Rattus, on the medial side of the shaft, opposite the indicating that at least some of the depo- fibular crest, that is an extension of the inner sition was post-Columbian. In all likelihood cnemial crest. There is a deep fossa retro- this specimen is Holocene in age and it could cristaUs on the proximal articular surface be very recent. and a deep fossa flexoria on the most prox- The tibiotarsus from Camagüey is defi- imal part of the caudal portion of the tibial nitely older, being from a bone breccia con- head. This specimen, too, is very close in taining thousands of bones of the rodent size and morphology to Scytalopus, but dif- Geocapromeys columbianus, as well as iso- fers in the following respects: ñbular crest lated remains of Capromys pilorides, C. longer, medial crest somewhat more dis- nana, Solenodon cubanus, and Edentata, tinct, inner cnemial crest with less promi- Rattus and Mus were absent in these de- nent excavation on the anterior tip, ridge posits, which date from the first two (of three) on the lateral side of the outer cnemial crest pluvial periods of the Upper Pleistocene. lacking, and inner cnemial crest not as nar- Comparative skeletal material ofScytalo- row at the base. These differences are some- podidae examined.•(Nxxxabcr of individ- what greater than between the fossil hu- uals in parentheses): Scytalopus unicolor (2, mérus and Scytalopus but might still fall USNM), S. femoralis (1, USNM), 5. ma- within the range of variation in that . gellanicus (1, USNM), S. argentifrons (3 The specimen also shows some similarity partial, USNM), albicollis (1, to Melanopareia. Without more fossil and USNM; 1, AMNH), Melanopareia elegans recent material we are hesitant to make a (2, USNM), Pteroptochus megapodius (2, positive identification of the Cuban mate- USNM), P. tarnii (1, USNM), Rhinocrypta rial as Scytalopus. lanceolata (2, AMNH). Discussion. •A tapaculo in Cuba presents Comparisons.•^oX\i the humérus and the an almost insurmountable zoogeographical tibiotarsus in the Scytalopodidae are dis- anomaly. The family Scytalopodidae (con- tinctive and easily separable from those of taining 11 genera and 17 species) appears most other (Feduccia and to be the most primitive group in the su- Olson 1982), being quite unlike any pas- perfamily Fumarioidea (Feduccia and Ol- serine known from Cuba. The fossil hu- son 1982) and is restricted to South Amer- mérus from the Isle of Pines agrees with that ica, except for two species of Scytalopus, in the Scytalopodidae in having the pectoral one found in eastern Panama and the other crest reduced, curved, and decidedly incised in western Panama and Costa Rica. The VOLUME 100, NUMBER 2 355

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'So -UC 356 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON family is most diverse in southern South stone fashion from continental areas. Even America, with the more northern species if this were the case, the avifauna of the tending to be montane in distribution. Greater AntiUes is preponderantly of North The suboscine (suborder Eu- and Central American derivation, a point rylaimi or auct.), which includes repeatedly emphasized by Bond (e.g. Bond the fumarioidea, and probably the entire 1934, 1948, 1963, 1978), whereas the Scy- order passeriformes, are believed to have talopodidae are South American. Besides originated in the Southern Hemisphere (Ol- which, it would be just as difficult for a son 1985b). There is no reason to believe species oí Scytalopus to get to a conjectural that the Scytalopodidae would ever have island and then to Cuba as to go there di- been present in North or Middle America rectly from the mainland of South America. prior to the closing of the Panamanian sea- Although drifting land masses have been way at the end of the Pliocene. (A supposed proposed on an ad hoc basis to explain the tapaculo from the Eocene of Wyoming does occurrence of certain taxa in the Antilles, not even belong in the Passeriformes, much such as the Insectívora (MacFadden 1980), less to the Scytalopodidae [Feduccia 1976].) to have pieces of land randomly hurtling Thus, any tapaculo found in Cuba would the odd taxon hither and yon about the Ca- probably have had to get there directly from ribbean hardly seems an advance over the South America. days when landbridges were constructed As a group, the tapaculos are terrestrially over most of the surface of the ocean for the adapted, with strong legs, reduced wings, same purposes. and weak powers of flight. The species of Yet how did a tapaculo get to Cuba? We Scytalopus are the smallest members of the are left with the old hypothesis of rafting, family, being tiny, skulking, wren-like birds which is an improvement over hypotheses that are practically flightless. The pectoral of drifting land masses or of landbridges at apparatus in Scytalopus is very reduced, the least in that rafts of floating vegetation would sternum has only a vestigial keel, and the surely be of more frequent occurrence than clavicles are unfused (Feduccia and Olson rafting land masses. Groimd sloths evi- 1982). In short, of all the thousands of dently swam or were rafted directly from species of passerine birds in the world, the South America to the Greater Antilles, as species of Scytalopus would seem to be the West Indian taxa are more closely re- among the very least capable of overwater lated to Miocene sloths of South America dispersal. Furthermore, the Scytalopodidae than to the Plio-PIeistocene taxa of North belong to a large superfamily (or suborder, and (Paula Couto 1967). depending on one's views), Fumarioidea The fact that ground sloths did not colonize (Ames 1971), no member of which occurs Jamaica is probably a result ofthat island's anywhere in the West Indies. having been located farther west and having The geological history of the Antillean re- been submerged from the middle Eocene to gion is extremely complex but there is still the early Miocene (Buskirk 1985), a fact that no convincing evidence of a former direct provides some indirect evidence corrobo- land connection between any of the Antilles rating the probable time of arrival of ground and the mainland of either North or South sloths in the Greater Antilles. Presumably America (Pregill 1981). Although various any factors that may have facilitated the models propose the existence of a "proto- dispersal of ground sloths at this time could Antilles" in the position of present day Mid- have aided a tapaculo as well. dle America (Rosen 1976, MacFadden 1980, No species similar to Scytalopus has ever Savage 1982), these have been projected as been reported historically in Cuba and it islands that received their fauna in stepping- would seem likely that any such bird must VOLUME 100, NUMBER 2 357 now be extinct. Given the possibly quite (Passeriformes).•Bulletin of the Florida State recent age of the specimen from the Isle of Museum Biological Sciences 23:139-228. Pines, it is conceivable that the species ex- Buskirk, R. E. 1985. Zoogeographie patterns and tec- tonic history of Jamaica and the northern Ca- isted into the historic period, only to fall ribbean. •Journal of Biogeography 12:445^61. prey to introduced predators such as rats, Feduccia, A. 1976. Neanis schucherti restudied: cats, and mongooses. However, because the Another Eocene piciform bird. Pp. 95-99 in S. two localities from which the Cuban tapacu- L. Olson, ed.. Collected papers in avian paleon- lo is known are nearly 500 km apart, it must tology honoring the 90th birthday of Alexander Wetmore.•Smithsonian Contributions to Pa- once have been widespread and possibly leobiology 27. may still exist in some remote mountainous , and S. L. Olson. 1982. Morphological sim- area of the island. ilarities between the Menurae and the Rhino- cryptidae, relict passerine birds of the Southern Acknowledgments Hemisphere.-Smithsonian Contributions to Zoology 366:1-22. We thank Rafael Alvarez, who first un- MacFadden, B. J. 1980. Rafting mammals or drifting dertook to sort the material from the Isle of islands?: Biogeography of the Greater Antillean insectivores Nesophontes and Solenodon. • Pines and originally recognized the familial Journal of Biogeography 7:1 i-22. affinities of the humérus described above. Olson, S. L. 1985a. A new species oî Siphonorhis Kurochkin's visit was supported in part by from Quaternary cave deposits in Cuba (Aves: the American Museum of Natural History Caprimulgidae).•Proceedings of the Biological (AMNH) and the Smithsonian Institution. Society of Washington 98:526-532. . 1985b. The fossil record of birds. Pp. 79- We are grateful to David W. Steadman for 238 in D. S. Famer, J. R. King, and K. C. Parkes, commenting on the manuscript. The pho- eds., Avian biology, volume 8. Academic Press, tographs are by Victor E. Krantz, Smith- New York. sonian Institution. Paula Couto, C. de 1967, Pleistocene edentates of the West Indies. • American Museum Novitates 2304:1-55. Literature Cited Pregill, G. K. 1981. An appraisal of the vicariance hypothesis of Caribbean biogeography and its Ames, P. L. 1971. The morphology of the syrinx in application to West Indian terrestrial verte- passerine birds. •Peabody Museum of Natural brates.•Systematic Zoology 30:147-155. History Yale University Bulletin 37:1-194, 21 Rosen, D. E. 1976. A vicariance model of Caribbean plates. biogeography.-Systematic Zoology 24:431- Bond, J. 1934. The distribution and origin of the 464. West Indian avifauna.•Proceedings of the Savage, J.M. 1982. The enigma of the Central Amer- American Philosophical Society 78:341-349. ican herpetofauna: Dispersals or vicariance?• . 1948. Origin of the bird fauna of the West Annals of the Missouri Botanical Garden 69: Indies.-Wilson Bulletin 60:207-229. 464-547. . 1963. Derivation of the Antillean avifau- na.•Proceedings of the Academy of Natural Sciences of Philadelphia 115:79-98. (SLO) Department of Vertebrate Zoolo- . 1978. Derivations and continental affinities gy, National Museum of Natural History, of Antillean birds. Pp. 119-128 in F. B. Gill, Smithsonian Institution, Washington, D.C. ed-, Zoogeography in the Caribbean. The 1975 20560; (ENK) Paleontological Institute of Leidy Medal Symposium.•Academy of Natu- ral Sciences of Philadelphia Special Publication the USSR Academy of Sciences, Prof- 13. sojuznaja 123, Moscow 117321, USSR. Brodkorb, P. 1978. Catalogue of fossil birds. Part 5

CORRIGENDA: p. 353 line 3 read "podida© "= Rhinocryptfdae auct." p. 354 read "Geocapromys" p. 356 lines 6-7 read "Furnarloldea" "Passeriformes"