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The Pliocene record of iguanian pleurodont lizards of South America is scarce, although it is plentiful during the Miocene, including extant genera. Here we describe a partial dentary from the Plio...

Only two giant vampire fossils are so far recognize at mid latitude in the late Pleistocene of South America. Both considered with reasonable doubt (cf., aff.) to Desmodus draculae. Here, a recently recovered dentary form the late Pleistocene of southeastern Buenos Aires, is confidently assigned to D. draculae. During the late Pleistocene D. draculae had a large distribution from Mexico to central Argentina, larger than that of extant D. rotundus.

The teiid genera Dicrodon and Teius possess transverse bicuspid posterior teeth on the dentaries and maxillae. In general, their dentition is considered to be comparable, and little attention has been given to their dental morphology. Here the dentition of Dicrodon is described in detail and compared to that of Teius. The dentition of Dicrodon differs from that of Teius in the following characters: both cusps are more concentrically placed (in occlusal view); the lingual cusp is developed on a crescent ridge; the crescent ridge may present mesial and distal protuberances; the lingual cusp is shorter (never as tall) as the labial cusp; and the intercuspid ridge is incomplete (missing in the lingual cusp). These characters allow the dental diagnosis of both genera. Fil: Brizuela, Santiago. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Kristukat, Ralf Christian. Staatliches Museum fur Naturkunde Stuttgart; Alemania

El trabajo llevado a cabo en la presente Tesis representa una puesta al día del registro fósil conocido de lagartos continentales (excepto Iguania) de Argentina, donde la identificación del material fue realizada empleando criterios modernos dentro de un marco cladístico y mediante el contraste directo con abundantes ejemplares actuales del grupo. Durante el desarrollo de la Tesis, se presenta en forma introductoria el marco sistemático y las relaciones filogenéticas de los lagartos, así como una actualización del registro conocido de lagartos fósiles en el mundo, y particularmente, en América del Sur y en Argentina. El objetivo general del trabajo de Tesis doctoral se resume en el estudio sistemático de los fósiles de lagartos continentales presentes en el territorio argentino bajo la consideración de las relaciones filogenéticas planteadas en la Tesis y basadas únicamente en caracteres osteológicos. Debido a que la mayor parte del material fósil estudiado corresponde a la familia Teiidae se describió escuetamente el cráneo del teido actual Tupinambis merianae. Si bien esta especie es ampliamente reconocida y su osteología ya ha sido descripta, aquí se describieron estructuras previamente no observadas. En particular, se describió la dentición de T. merianae, la cual no había sido previamente descripta en detalle teniendo en cuenta todas sus variaciones, que fueron de particular importancia para la interpretación del material fósil. También se reconocieron las diferencias en las características dentarias y estructuras postcraneanas de otros teidos., Facultad de Ciencias Naturales y Museo

Squamates form a substantial part of the present-day South American herpetofauna, and their fossils constitute an indispensable evidence for understanding the origin and evolution of the main taxa. Squamates are relatively common in Miocene localities of Patagonia, especially in levels of the late early Miocene Santa Cruz Formation. In this contribution, remains of the three species of the extinct iguanid Erichosaurus Ameghino 1899 (E. diminutus, E. bombimaxilla and E. debilis) are redescribed, and new squamate specimens are reported for first time. The genus Erichosaurus is considered invalid. Erichosaurus debilis, E. diminutus and a new specimen are recognized as indeterminate species of the extant polichrotine Pristidactylus, whereas E. bombimaxilla remains as an indeterminate iguanid. Snakes are represented by an indeterminate colubrid. All these specimens, together with a tupinambine teiid previously described for the same formation, represent the southernmost fossil record of squamates in South America and indicate the occurrence of the iguanid Pristidactylus, the teiid Tupinambis and the colubrid snakes south to their present distribution as back as during the early Miocene. Fil: Albino, Adriana Maria. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Brizuela, Santiago. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Vizcaíno, Sergio Fabián. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Squamata are known from South America since the Cretaceous, but their fossil record has an occurrence gap between the late Eocene and early Miocene. Fossils recovered from the Sarmiento Formation (Deseadan South American Land Mammal Age, late Oligocene) at Cabeza Blanca (45°S) partially fill this interval. The squamates recovered from Cabeza Blanca include both lizards (an indeterminate Iguanidae and a probable Iguaninae) and snakes (Madtsoiidae). If these taxonomic assignments are correct, the presence of an Iguaninae at such a latitude is unexpected because these lizards are presently absent from Argentine territory. The madtsoiid, here referred to Madtsoia, would extend the Cenozoic record of this genus back to around 16 Ma. The squamate fauna from Cabeza Blanca is compatible with warm and humid environments inferred for the Patagonian Deseadan. 众所周知，有鳞目在南美自白垩纪起就存在了，但他们的化石记录在晚始新世和早中新世之间有一个间断。从卡韦萨布兰卡（45°S）的Sarmiento组采得的化石（渐新世晚期Deseadan南美陆地哺乳动物时代）填补了这一空白。从卡韦萨布兰卡采得的有鳞类包括蜥蜴（不确定Iguanidae和可能的Iguaninae）和蛇（Madtsoiidae）。如果这些分类群的鉴定是正确的，Iguaninae在这样一个纬度的存在是意想不到的，因为这些蜥蜴目前在阿根廷领地缺失。这些madtsoiid，这里被称为Madtsoia，将该属的新生代记录往回推约16Ma。卡韦萨布兰卡的有鳞动物群适应于所推断的巴塔哥尼亚Deseadan温暖潮湿的环境。 Fil: Albino, Adriana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina Fil: Brizuela, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina

The evolution of squamates in South America is the result of the complex geological and paleoclimatic history of this part of the world. The incomplete and episodic fossil record allows us to know only a small part of this evolution. Most Mesozoic squamate remains come from the Patagonian region, but remarkable specimens have also been recovered from Brazil. Both major squamate clades (Iguania and Scleroglossa) are present in the South American Mesozoic. Remains of Mesozoic snakes are common and diverse in Cretaceous deposits, including some of the most primitive terrestrial forms. Paleogene and Neogene squamate remains have been recognized from Argentina, Bolivia, Brazil, Colombia, Ecuador, Peru, and Venezuela. Paleogene lizard record appears to be scarce in comparison to that of the Mesozoic, whereas snakes show an important Paleogene diversity. At least two extant boid snakes appeared during this epoch (Boa and Corallus). The South American Miocene included some extant genera of Iguania, Teiidae, and Boidae but extinct genera were also present. “Colubrids” appeared at the early Miocene, whereas the first viperid is known from the late Miocene. Most of the Paleogene and early Neogene squamate families and genera have been recognized outside their current range of distribution following favorable climatic conditions for ectothermic vertebrates. During the latest Miocene and Pliocene few extant squamate taxa are found to occur outside their present distribution. The earliest amphisbaenian of South America is known from the Pliocene. Most Pleistocene and Holocene squamate remains are assigned to living genera, and some extant species were recognized. Anat Rec, 297:349–368, 2014. © 2014 Wiley Periodicals, Inc.

The Pliocene squamate reptiles of the Atlantic coast between Mar del Plata and Miramar, Buenos Aires province, Argentina. Teiid and amphisbaenian reptiles from Pliocene beds along the coast of the Buenos Aires province, between Mar del Plata and Miramar, are described. They include previously listed remains as well as unreported material belonging to old collections. They document the presence of the teiid genus Tupinambis in Upper Chapadmalalan and Marplatan (Vorohuan) units. The extinct species “T. onyxodon” Kraglievich 1947 is considered invalid herein; also, previous cites of T. merianae are reevaluated as Tupinambis sp.. Remains of the amphisbaenid Amphisbaena sp. are identified in Upper Chapadmalal beds; they represent so far the earliest record of amphisbaenians in South America.

The terrestrial lizard fossil record of Gondwana is very scarce. Few lizards, from mostly fragmentary fossils, have been identified in Madagascar, Tanzania, Morocco, South Africa, India and South America. Among the South American specimens there are basal Squamata forms (Olindalacerta and Tijubina) and a possible iguanid (Pristiguana) form Brazil. In Argentina gondwanian terrestrial lizards are represented by a putative iguanid and a small, poorly preserved dentary. This last specimen, recovered from the Anacleto Formation (Neuquen Group, Rio Colorado Subgroup) in vicinity of the locality of Cinco Saltos (Rio Negro Province), is here described formally. Comparisons with extant lizards indicate more affinity of the fossil with the Scincomorpha (non Scincophidia) than with any other group of lizards. This finding suggests that lizards were probably better represented and more diverse in the Mesozoic of South America than previously thought, although the fossil record is, at the moment, much poorer than in Laurasia.

typicus," but he never described the specimens in any detail or figured them. Due to the fragmentary nature of the material, the affinities of both monotypic genera have been contentious. In a series of papers, Ameghino variously assigned "Diasemosaurus" to the lizard families Agamidae (Ameghino, 1893, 1899) or Iguanidae (Ameghino, 1898), and he considered "Dibolosodon" to be close to either the Proterosauridae (Ameghino, 1893) or Champsosauridae (Ameghino, 1898). Subsequent authors have regarded both genera as lizards. Romer (1956, 1967) tentatively included "Diasemosaurus" within the lizard family Teiidae, although he provided no characters to support those assignments. Estes (1983) regarded "Diasemosaurus" and "Dibolosodon" as nomina dubia, with the former placed within the teiid subfamily Tupinambinae and the latter considered Lacertilia incertae sedis. Estes (1983) apparently was unaware of Ameghino's (1893) original descriptions for both taxa, because he did not cite that paper; instead, he incorrectly listed Ameghino (1898) as the author for both names. Gasparini and Biez (1975) and Biez and Gasparini (1977, 1979) suggested that one of the "Diasemosaurus" specimens (MACN-A 5806-a) showed affinities with the Miocene-Recent tupinambine genus Tupinambis. Donadio (1984) believed that same specimen pertained to a new species of Tupinambis, which he informally named "Tupinambis occidentalis"; a formal description of that species was never published. The only other significant mention of either "Diasemosaurus" or "Dibolosodon" in the literature is Gasparini et al.'s (1986) report that "Diasemosaurus" occurs at a second Patagonian Miocene locality (Gaiman), farther to the north in Chubut Province (Fig. 1). However, Brizuela and Albino (2004) identified only Tupinambis at the Gaiman locality. In this paper we re-describe, figure, and discuss the taxonomic affinities of the three type specimens of "Diasemosaurus occidentalis" and "Dibolosodon typicus."

Remains of teiids assignable to the Tupinambinae (Tupinambis sp. or Crocodilurus sp.) are here described from the middle Miocene Collón Curá Formation at Cañadón del Tordillo, in Neuquén province, Argentina. No tupinambine species presently inhabits the region of the fossil locality. The fossils represent the westernmost distribution of fossil tupinambine teiids in Patagonia, enlarging the known geographical distribution of the teiids through the Miocene in a longitudinal range. Also, they constitute the first record of lizards from the Colloncuran SALMA, partially filling the record of tupinambine teiids for the South American Miocene.

The most abundant and diverse records of teiids in the South American Miocene are from early and middle Miocene of Patagonia (Argentina) and Colombia. Only two genera of tupinambines are recognized: Paradracaena and Tupinambis. In this contribution, we describe remains assigned to Tupinambis from the late Miocene Cerro Azul Formation. The fossils were collected in exposures of this unit at several localities in the province of La Pampa, central Argentina. Evolutionary history and biogeography of South American tupinambines were affected by the environmental-climatic change subsequent to the uplift of the Andes. Among the taxa represented in the Miocene, Paradracaena became extinct, whereas Tupinambis survived restricted to environments with a more benign climate, disappearing from Patagonia but not from central Argentina.

The Trelew Member of the Sarmiento Formation (early Miocene) at Gaiman, Chubut province, Argentina, is one of the most prolific South American Cenozoic localities for squamatan remains. Within the lizards, at least three teiids have been cited, but the material has never been described. In this paper, mainly fragmentary dentaries and maxillae from this site are identified as belonging to the genus Tupinambis. These constitute the earliest record of this extant teiid genus. Tupinambis has a wide range of distribution through South America but is presently absent in the Gaiman area. Its occurrence in the early Miocene of Patagonia indicates warmer and more humid climatic conditions than today.

The evolution of squamates in South America is the result of the complex geological and paleoclimatic history of this part of the world. The incomplete and episodic fossil record allows us to know only a small part of this evolution. Most Mesozoic squamate remains come from the Patagonian region, but remarkable specimens have also been recovered from Brazil. Both major squamate clades (Iguania and Scleroglossa) are present in the South American Mesozoic. Remains of Mesozoic snakes are common and diverse in Cretaceous deposits, including some of the most primitive terrestrial forms. Paleogene and Neogene squamate remains have been recognized from Argentina, Bolivia, Brazil, Colombia, Ecuador, Peru, and Venezuela. Paleogene lizard record appears to be scarce in comparison to that of the Mesozoic, whereas snakes show an important Paleogene diversity. At least two extant boid snakes appeared during this epoch (Boa and Corallus). The South American Miocene included some extant genera of Iguania, Teiidae, and Boidae but extinct genera were also present. "Colubrids" appeared at the early Miocene, whereas the first viperid is known from the late Miocene. Most of the Paleogene and early Neogene squamate families and genera have been recognized outside their current range of distribution following favorable climatic conditions for ectothermic vertebrates. During the latest Miocene and Pliocene few extant squamate taxa are found to occur outside their present distribution. The earliest amphisbaenian of South America is known from the Pliocene. Most Pleistocene and Holocene squamate remains are assigned to living genera, and some extant species were recognized.