An Accumulation of Bone Remains of Two Liolaemus Species (Iguanidae) in an Holocene Archaeological Site of the Argentine Puna
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An accumulation of bone remains of two Liolaemus species (Iguanidae) in an Holocene archaeological site of the Argentine Puna Adriana M. Albino1, Débora M. Kligmann2 Abstract. An accumulation of iguanian bone remains was found inside a rodent burrow in an Holocene archaeological site of the Argentine southern Puna. Characters of the preserved bones suggest that a minimum of two species of the Liolaemus genus is represented. One of them is undoubtedly attributed to the montanus group, probably L. poecilochromus or L. andinus.The finding of Liolaemus bone remains in the Argentine Puna Region represents the first record of this genus in an archaeological site of South America and suggests that specimens of at least two Liolaemus species exploited the same refuge simultaneously, including both adult and juvenile individuals. Reptile remains found in archaeological sites layer where the microvertebrates were found are relevant for understanding the relation- (Kligmann et al., 1999). These remains, that ac- ship between indigenous groups and their en- cording to the number of preserved right den- vironment as well as to interpret the taphon- taries belong to at least 71 individuals (Klig- omy of microvertebrate fossil assemblages. The mann et al., 1999), were concentrated in a sur- findings of small iguanids in South American face smaller than 1 m2 on the SW sector of archaeological sites are still scarce. For Ar- the excavation. A rodent burrow, probably cor- gentina, Van Devender (1977) describes an iso- responding to Ctenomys, was observed in the lated dentary belonging to the iguanid Leiosau- same area. rus belli (Gruta del Indio cave, eastern slopes Kligmann et al. (1999) preliminarly assigned of the Andes), whereas Mengoni Goñalons and the whole assemblage to the iguanid of the Silveira (1976) mention the presence of indeter- genus Liolaemus; however, they did not provide minate iguanids in Cueva de las Manos, Patag- any unambiguous synapomorphy to support this onian region. assignation. They offered neither comparisons Alero 12 is a rockshelter located at 3980 m nor illustrations of the specimens. The aim of asl in the Puna Region, Tinogasta Department, this note is to discuss the generic and species- Catamarca Province, Argentina (68◦07W and group level systematic position of the lizard 26◦55S). This archaeological site stands out by remains found at Alero 12. the presence of an unusual abundance of lizard The methodology followed for sample collection in the bone remains (99.2% of the total microfaunal field and during sample analysis in the laboratory is ex- assemblage) found in an excavated surface of plained in Kligmann et al. (1999). Stereoscopic microscope 4m2 (Kligmann et al., 1999). The only radio- and camera lucida were used for the descriptions and illus- ± trations presented in this note. carbon date available for the site (590 45 Skeletal materials used for fossil identification are listed BP, LP-880) comes from the same stratigraphic in the Appendix. The systematic arrangement follows Schulte et al. (2003). An asterisk denotes a metataxon. The abbreviations used are: HAA, private herpetological collec- 1 - CONICET – Departamento de Biología, Universidad tion of Adriana Albino; MCN, Museo de Ciencias Natu- Nacional de Mar del Plata, Funes 3250, 7600 Mar del rales, Universidad Nacional de Salta; SA-ICA/Ca, Sección Plata, Argentina Arqueología, Instituto de Ciencias Antropológicas, Facultad e-mail: [email protected] de Filosofía y Letras, Universidad de Buenos Aires. 2 - CONICET – Sección Arqueología, Instituto de Ciencias The studied sample (SA-ICA/Ca 01) consists of 13 pari- Antropológicas, Facultad de Filosofía y Letras, Uni- etals, one pterygoid, 21 frontals, 33 jugals, one osteoderm, versidad de Buenos Aires, 25 de Mayo 217, 3er piso, 19 quadrates, one braincase remain, 11 premaxillae, 80 C1002ABE Capital Federal, Argentina maxillae, 151 dentaries, 39 mandible fragments, 428 ver- © Koninklijke Brill NV, Leiden, 2007. Amphibia-Reptilia 28 (2007): 154-158 Also available online - www.brill.nl/amre Short Notes 155 tebrae, 27 coracoids, 53 pelvic girdles, 848 long bones, six first record of this genus in a South American metatarsals and one phalanx. archaeological site. The systematic position of the lizard remains In some of the dentaries of Alero 12 the Li- from Alero 12 is the following: olaemus synapomorphy cannot be observed be- Iguania Cope, 1864 cause the posterior part is either broken or of Iguanidae Boulenger, 1885 doubtful extension (fig. 1F). These dentaries Tropidurinae* Bell, 1843 bear an open Meckel’s groove and flared and Liolaemini Frost and Etheridge, 1989 deeply cuspidate teeth as in some Liolaemus Liolaemus Wiegmann, 1834 (Etheridge, 2000; Albino, unpublished data) Most remains belong to mature individuals, and Phymaturus species (Etheridge, 1995). P. although juvenile specimens are also present antofagastensis currently lives in Tinogasta De- (Kligmann et al., 1999). The assignment of partment, at 4000 m asl (Cei, 1993). As these the specimens to the Liolaemini is based on remains are of uncertain generic filiation, they the following combination of character states may belong to either a Liolaemus species or (Estes et al., 1988; Frost and Etheridge, 1989) Phymaturus cf. P. antofagastensis. (fig. 1): skull roof bones not strongly rugose; Within the dentary remains undoubtedly as- frontals fused and constricted between the or- signed to Liolaemus, the open Meckel’s grooves bits; trapezoidal parietal roof; pleurodont den- (fig. 1B, C) exclude them from the chiliensis tary and maxillary teeth, not fused to the un- group (Etheridge, 1995; Lobo, 2001). Among derlying bones; dentaries not expanded onto these dentaries, two typologies in the posterior the labial face of the coronoids; open Meckel’s teeth as well as in fragmentary maxillae have groove; well-developed labial blade of the coro- been recognized. noid; splenial extended anteriorly more than Typology 1. Tricuspidate, parallel tooth crown 1/6 of the tooth row length on the dentaries; sides, central main cusp and moderate lateral transverse processes anterior to the caudal auto- cusps framed by short grooves (fig. 1B, Da). tomy fracture planes and presence of a posterior Most of the complete dentaries have this tooth coracoid fenestra. A posterior extension of the typology. dentary to the level of the coronoid’s superior Typology 2. Deeply tricuspidate, flared tooth apex is established in most remains (fig. 1B, C). crown sides, central main cusp and strongly This is a Liolaemus synapomorphy (Etheridge, defined lateral cusps framed by long and clear- 1995). cut grooves (fig. 1C, Db). Liolaemus is the richest lizard genus in South Montanucci (1968), who noted ontogenetic America including more than 160 described differences in the dentition of the iguanid lizard species (Schulte et al., 2000). It ranges from the Ctenosaura similis, gave a possible explana- high Andean mountains of Peru and Bolivia in tion for this variation. In young animals, the the north to northern Tierra del Fuego Island in teeth are highly cuspidate and occur more ante- the south, and from the Pacific beaches in the riorly along the tooth row than in older lizards. west to the sandy Atlantic beaches of Argentina, Nevertheless, ontogenetic variation in the Li- Uruguay, and Brazil in the east (Donoso Barros, olaemus tooth morphology has not been re- 1966; Cei, 1993). The earliest fossil record of ported. Interspecific differences in the degree this genus comes from the early Miocene of of cusp development were found to be statisti- Patagonia (Albino, unpublished data). It has cally significant in the Uma genus (Zalusky et also been recognized in the late Pleistocene- al., 1980). Among the species of the genus Lio- early Holocene of the Pampean Region (Albino, laemus, the tooth morphology shows a great de- 2005). The finding of Liolaemus bone remains gree of interspecific variation (Albino, unpub- in the Argentine Puna Region represents the lished data), although they are not largely doc- 156 Short Notes Figure 1. A, frontal in dorsal view; B, right dentary in labial (a) and lingual (b) views; C, left dentary in labial (a) and lingual (b) views; D, tooth typology 1 (a) and 2 (b); E, left tibia attributed to the montanus group in dorsal view; F, Lioaemus sp. or Phymaturus cf. antofagastensis, right dentary in labial (a) and lingual (b) views. umented (Etheridge, 2000; Lobo and Abdala, ution quite likely. Therefore, it is highly proba- 2001). Since the size of the dentaries with both ble that the Liolaemus species found in Alero tooth typology 1 and 2 is similar, thus ruling out 12 still live in the Puna of Tinogasta Depart- age considerations, the presence of more than ment, at altitudes higher than 3500 m asl. The one species belonging to the Liolaemus genus is species of the montanus group (sensu Etheridge, established. 1995) that are distributed in the area of Alero 12 All preserved tibias have a posterior distal are L. dorbignyi, L. poecilochromus and L. and- bladelike process (fig. 1E) (Keller and Krause, inus (Cei, 1993). The size of the dentaries of 1986), a synapomorphy of the montanus group the specimens recovered from Alero 12 is sig- (Etheridge, 1995). Hence, at least one of the nificantly smaller than that of the specimens of species would belong to this group. L. dorbignyi, while it is compatible with that of The fact that the radiocarbon date available both L. poecilochromus and L. andinus species. for the archaeological site is very recent makes The tooth typology 1 described for the dentaries the absence of modifications in the taxa distrib- of Alero 12 is shown by the teeth of L. poe- Short Notes 157 cilochromus. The lack of available osteological to 73, HAA 75, HAA 90-91; L. ornatus: MCN 773-775; L. material of L. andinus prevents a comparison petrophilus: HAA 84, HAA 112; L. poecilochromus:MCN 249-250, MCN 280; L. rothi: HAA 81; L. somuncurae: with this species.