Pachyarmatheriidae

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Pachyarmatheriidae
Temporal occurrence
Middle Miocene to Lower Holocene
14 million years to 10,000 years
Locations
Systematics
Land vertebrates (Tetrapoda)
Mammals (mammalia)
Higher mammals (Eutheria)
Sub-articulated animals (Xenarthra)
Armored siderails (Cingulata)
Pachyarmatheriidae
Scientific name
Pachyarmatheriidae
Fernicola , Rinderknecht , Jones , Vizcaíno & Porpino , 2018

The Pachyarmatheriidae are an extinct family from the order of armored collateral animals , to which the armadillos still existing today belong. It occurred from the Middle Miocene around 14 million years ago to the end of the Pleistocene around 10,000 years ago. Their main area of ​​distribution included the central and northern part of South America and the southern part of North America and thus landscapes under warm and humid climatic conditions. Outwardly, the animals resembled today's armadillos and were roughly the same size. An important difference is the design of the back armor. This consisted of two rigid parts in the area of ​​the shoulder and pelvic girdle, which overlapped in a hinge-like manner approximately above the middle of the body . As a result, there were no movable bands between the fixed armor sections, which are characteristic of the armadillos. The very thick bone plates that make up the shell are also typical. The skeleton construction indicates that the representatives of the family represented more generalized graves, which probably ate mainly ants and termites . The family was scientifically introduced in 2018 and currently consists of two genera. Presumably it is more closely related to the Glyptodontidae and the Pampatheriidae .

features

General and height

The representatives of the Pachyarmatheriidae may have looked more like today's armadillos than the glyptodons . Their body size largely corresponded to that of a recent long-nosed armadillo such as the nine-banded armadillo . The head-trunk length is estimated at 50 to 60 cm, the weight should have been around 10 to 15 kg.

Skeletal features

Skeletal finds from Pachyarmatherien are still relatively rare today. This also applies to the skull, of which only individual fragments are regarded as probably belonging to these armored articulated animals. These indicate that a crescent-shaped bulge apparently appeared on the occiput , which can be found in the long-nosed armadillos through corresponding formations. The lower jaw had a graceful and blade-shaped structure. In contrast to all other representatives of the armored articulated animals, there were no alveoli for the teeth, so that he was most likely toothless. This trait is typical of today's anteaters as a related group. The symphysis at the anterior end for the joint between the two halves of the lower jaw was not fused and significantly reduced. This in turn largely corresponds to the long-nosed armadillos. Consistent with these and in contrast to the anteaters, the coronary process rose far and was well above the articular process. The latter stood just a little above the horizontal bone of the lower jaw. Anteaters, on the other hand, have strongly receded processes of the ascending lower jaw branch.

The postcranial skeleton has also only survived in fragments. The well-known thoracic and lumbar vertebrae, with a few exceptions that belong to Neoglyptatelus , were free and not fused, but fused vertebrae are a characteristic of the glyptodons. The humerus was massive and had a short but strong deltopectoral ridge on the shaft. At the ulna there was an extremely large upper articular process ( olecranon ), which reached almost the length of the rest of the bone and exceeded the corresponding formations in the armadillos. Accordingly, a total of 11.5 cm long specimen had a 5.7 cm long olecranon. The thigh bone was marked by a clear third rolling mound about mid-shaft height. The great rolling mound towered over the joint head, which in turn sat on a weakly pronounced neck. The lower end of the joint showed no lateral widening, consistent with the glyptodonts and pampatheria . The tibia and fibula were fused together at the ends. There was also a massive outer ankle . The full known hind foot had five rays, of which the innermost and outermost were the shortest, the second and third the longest. This means that the central ray is not emphasized, which is particularly strong in many burrowing animals such as some armadillos. The end links of the toes and some of the fingers found all had an elongated shape. Thus, they refer to once formed claws that were possibly narrower on the hands than on the feet. There were no noticeable differences in size between the individual beams. The formation of claws corresponds to that of the armadillos and differs from that of the glyptodons with their hoof-like formations. In contrast to the armadillos, the last phalanxes of the Pachyarmatherien ended much more blunt.

tank

Comparison of osteoderms of Glyptodontidae and Pachyarmatheriidae: Glyptotherium on the left , Panochthus in the middle , Pachyarmatherium on the right
Osteoderms of Pachyarmatherium in different views and with histological cross-sections

Like all armored articulated animals, the Pachyarmatherien were characterized by armor on the back and also the tail. A fully preserved back armor from Neoglyptatelus was 55 cm long and 30 cm high above the middle. At the front and rear ends, the height was 12 and 14 cm, respectively. The back armor or carapace consisted of a fixed shoulder and back shield, which slightly overlapped in the middle. This is an important difference from the armoradillo and pampatheria carapaces, in which a different number of movable bands are formed between the fixed armor sections, or from that of the glyptodons with their generally rigid carapace. The armor was made up of individual small bone plates or osteoderms, often hexagonal in shape. Their size varied mostly between 0.8 and 3.2 cm in length, between 0.9 and 2.9 cm in width and between 0.5 and 1.8 cm in thickness. The largest osteoderms were in the area of ​​the back line. A central pattern of polygonal to rounded shape was often formed on the surface, which took up about half the size of the entire bone platelet and was off-center. This central pattern was surrounded by a varying number of smaller border patterns. The lower edge of the shoulder and pelvic shield formed one or two rows of osteoderms, the outermost of which had a pentagonal outline and were not patterned. The outermost rows at the rear end of the shoulder shield and the front end of the pelvic shield, which formed the articulation surface of the two armor parts, deviated from this. On the one hand, this had a concave-convex corrugated surface on the underside of the shoulder shield, which corresponds to a similarly shaped surface on the top of the pelvic shield. This enabled the shoulder shield to overlap the pelvic shield and a hinge-like contact zone was created between the two, which allowed certain movements of the armor sections to one another.

The tail was also wrapped in armor. In the front area it consisted of individual rings from two rows of osteoderms. Each ring enclosed a caudal vertebra. The size of the rings and the bound bone platelets decreased towards the rear of the tail. There were no more rings at the tip of the tail. Here the bone platelets formed a kind of tube. All the bone platelets of the tail armor had a smooth surface without any pattern.

In cross-section, each bone platelet showed several layers, analogous to the formations in armadillos, glyptodonts and pampatheria. A solid layer of bone formed the upper and lower ends. Growth zones were found in the upper bone layer, and they also ran through individual canals in which hair follicles were probably located . The lower bone layer was composed of compact collagen bundles . Between the two there was an area with a cancellous structure, which, however, unlike the glyptodons, was rather poorly developed.

distribution

The Pachyarmatheriidae are passed down from South America as well as from Central and North America . The South American discovery areas extend from Uruguay in the south to the north via Brazil and Peru to Colombia and Venezuela . In Central America, evidence comes from Costa Rica , in North America remains of the animals have so far mainly been discovered in the south-eastern part of the continent in Florida and South Carolina . The time depth ranges from the Middle Miocene around 14 million years ago to the transition from the Pleistocene to the Holocene around 10,000 years ago.

Paleobiology

Pachyarmatherium osteoderms with traces of feeding caused by fleas

In addition to the generally armadillo-like appearance of the pachyarmatheria, there are individual references to a burrowing way of life on the skeleton. The most obvious is the extensive process of the upper joint end ( olecranon ) of the ulna , which takes up almost the length of the rest of the bone. The corresponding front leg element in the six-banded armadillo has similar dimensions . Typically, a long olecranon increases the leverage of the forearm. In contrast, the hand and foot lack a significantly longer central ray, which is often found in burrowing animals. The last phalanges of the fingers and toes, which are strong but largely blunt, speak against exceptionally well-developed burial properties. Presumably, the Pachyarmatherien were more generalized graves that mostly scratched the underground, comparable to today's nine-banded armadillo . The rigid and overlapping armor parts prevented a significant flexion of the body, unlike the armadillos with their flexible ligaments. The hinge-like connection between the front and rear armor sections allowed movement in opposite directions over a length of 25 mm. Up and down movements of the body were even more restricted. However, they must not have been so clearly limited as in the case of the glyptodons, whose firmly fused armor and equally fused spine hardly support such movements. It is possible that the movement restrictions of the Pachyarmatheria increased in the course of the tribal history , since early representatives like Neoglyptatelus showed a more extensive armor joint than later ones like Pachyarmatherium .

The toothless, blade-shaped lower jaw differs significantly from that of the armadillos, which still have pin-like teeth. This characteristic is similar to the anteaters , which have a way of life that is highly specialized in ants and termites (myrmecophagia), whereby this special, toothless lower jaw was created due to the lack of chewing processes. With them, however, the joint connection to the skull is also greatly reduced, which was not the case with pachyarmatheries. From this it can be concluded that the representatives of the Pachyarmatheriidae followed a clearly myrmecophage diet, which was more developed than in numerous armadillos, but was not as pronounced as in the anteaters.

Secondary feeding traces, which can be traced back to parasitism , can be found on individual bone platelets of the Pachyarmatherien . These are mostly holey structures, as they are caused today in the armadillos by fleas of the genus Tsunga . Other structural surface changes can be traced back to the disease-related effects of bacteria and fungi . The same is true of extinct armadillos and glyptodons.

Systematics

External system

Internal system of armored articulated animals according to Fernicola et al. 2018
  Cingulata  

 Dasypodidae


   

 Chlamyphoridae


   
  Pachyarmatheriidae (†)  

 Neoglyptatelus


   

 Pachyarmatherium



  Glyptodonta  

 Pampatheriidae (†) 


   

 Glyptodontidae (†) 






Template: Klade / Maintenance / Style

The Pachyarmatheriidae represent a family within the order of armored secondary animals (Cingulata). This order, which was once rich in forms in South and North America, also includes the Glyptodontidae , Pampatheriidae , Peltephilidae and Palaeopeltidae , all of which are extinct. The armadillos (Dasypoda) are the only recent representatives to have survived. The armored articulated animals are in turn in the superordinate order of the articulated animals (Xenarthra), which also includes the tooth arms (Pilosa) with today's sloths (Folivora) and the anteaters (Vermilingua). The secondary articulated animals represent one of the four main lines of the higher mammals , which stands opposite the other three (collectively as Epitheria ) as a sister group . A general commonality of the secondary articulated animals can be found in the eponymous xenarthric joints (secondary joints, also xenarthral) on the articular processes of the posterior thoracic and lumbar vertebrae. The origin of the secondary articulated animals has not yet been clarified. They occurred fossilized in South America in the Paleocene more than 56 million years ago, and the finds are attributed to the armadillos. Molecular genetic investigations have shown that the secondary animals had split off from the other higher mammals as far back as the lower Cretaceous , around 103 million years ago. The armadillos as the closest relatives of the Pachyarmatheriidae living today separated from the common line with the tooth arms at the beginning of the Paleocene about 65 million years ago.

The internal structure of the armored articulated animals is not fully understood. The Pachyarmatherien can be assigned a close relationship to the Glyptodonts and the Pampatherien due to the skeleton construction and the armor design, as their sister group they are to be assumed. The close connections are expressed, among other things, in some individual features of the musculoskeletal system, for example on the thigh bone , the talus and the calcaneus . Then there are the missing movable ligaments and the thick bone plates of the shell. However, the lack of movable armor sections is not entirely clear, as this can be a derived feature of both the Pachyarmatherien and the Glyptodon. The glyptodonts and pampatherias are considered to be more closely related within the armored articulated animals, this is supported, among other things, by the structure of the teeth and the design of the ear. Both are therefore combined to form the superordinate group of the Glyptodonta. According to skull morphological investigations, the glyptodonta are embedded more deeply in the armadillos and have a closer relationship to euphractin armadillos such as the six-banded armadillo or the bristle armadillos . Being part of the armadillos had also molecular genetic confirm, in contrast to the results of the skeletal anatomy, however, a closer relationship with the revealed here tolypeutinen ( armadillos and cabassous ) and chlamyphorinen (Gürteltmulle) armadillos. As a sister line of the Glyptodonta, the Pachyarmatherien would also be very close to the armadillos.

Internal system

The Pachyarmatheriidae were introduced as an independent family in 2018 by Juan C. Fernicola and fellow researchers. It was preceded by the considerations that Pachyarmatherium and Neoglyptatelus are much closer to each other than originally assumed due to their typical design of the osteoderms. Pachyarmatherium was defined in 1995 by Kevin F. Downing and Richard S. White based on finds from the Leisey Shell Pit in Hillsborough County and Haile 16A fossil deposit in Alachua County , both located in the US state of Florida . At that time, the authors put their new genus in the closer armadillo family. The naming of Neoglyptatelus goes back to Alfredo A. Carlini and colleagues and is based on finds from La Venta in Colombia . The work team around Carlini advocated a very basic position of the new form within the Glyptodonts and connected them with the primeval subfamily of the Glyptatelinae , of which Neoglyptatelus was considered to be the youngest member of the family . Sergio F. Vizcaíno first suspected in 2003 that both Pachyarmatherium and Neoglyptatelus are closely related, and Kleberson de Oliveira Porpino made a similar statement six years later . However, in the following period, especially for Pachyarmatherium, the systematic position varied depending on the author between the armored collateral articulated animals with an unsafe position, the glyptodons or the armadillos. Fernicola and colleagues then united both genera under the family of Pachyarmatheriidae. The family name refers to the genus Pachyarmatherium as a nominate form . Their scientific name goes back to the Greek language and means something like παχύ- ( pachy- ) for "thick", άρμα ( arma ) for "chariot" and θηρίον ( thērion ) for "animal". The name thus refers to the thick armor.

The family is currently composed of two types:

  • Family: Pachyarmatheriidae Fernicola, Rinderknecht, Jones, Vizcaíno & Porpino , 2018

It is thought that the other members of the Glyptatelinae classified as primitive Glyptodonts, namely Glyptatelus and Clypeotherium , also belong to the Pachyarmatherien. Both taxa date to the Eocene and are based on only a few osteoderms, which, like the Pachyarmatherien, are relatively thick and have a decentralized pattern. However, histological examinations show a stronger similarity to the armor elements of the glyptodons.

Tribal history

The origin of the Pachyarmatheriidae is largely unknown. The group is first tangible in the Middle Miocene around 14 million years ago. This is Neoglyptatelus that was found in La Venta , an important fossil deposit on the central reaches of the Magdalena River in Colombia . The fossil material recovered here includes numerous individual osteoderms and the rest of the tail armor. The landscape in which this earliest representative lived consisted of forests that extended to flood plains and grew under the influence of warm and humid climates. Parts of the armor of the back and tail from the Sincelejo Formation in the coastal region of Colombia possibly belong to the Upper Miocene . At this point in time, the genus had spread very far into the south of the continent and is covered with bone platelets from eroded sands of the Camacho Formation in the mouth of the Río de la Plata in Uruguay . The same rock unit also brought to light one of the most complete finds to date: a skull-less partial skeleton with almost complete back armor and tail armor. The deposits of the Camacho Formation emerged in a similar landscape to that being reconstructed for La Venta. Their age is given as 8 to 6.8 million years. Likewise, remains of Neoglyptatelus from the same period come from the southwestern Amazon basin of Brazil .

The genus Pachyarmatherium can be documented for the first time in the transition from the Pliocene to the Pleistocene in South America. 184 bone chips alone were uncovered in the asphalt pits of El Breal de Orocual in northeastern Venezuela . The individual pits in the region were built at different times. As a result, the shape has been proven there for more than three dozen osteoderms until the end of the Pleistocene. In addition, fossil remains of Pachyarmatherium from northern Venezuela are documented, for example from the karst caves of Cerro Misión in the state of Falcón , as well as from north-eastern Peru . Some localities in northeastern Brazil refer to the most recent finds of the genus and at the same time the entire family . While the osteoderms of Fazenda Nova in the state of Pernambuco are still between 59,000 and 64,000 years old according to radiometric data, the skeletal and armored remains of Lajedo da Escada in the state of Rio Grande do Norte probably belong to the transition from the Pleistocene to the Holocene .

Like many other mammals originally endemic to South America , the Pachyarmatheriidae also came to North America in the course of the Great American Fauna Exchange . This began in the Pliocene around 3.5 million years ago when a land bridge was formed between the two continental masses on the Isthmus of Panama . Individual bone platelets from Pachyarmatherium from Costa Rica , for example from the region around Buenos Aires del cantón de Palmares, belong to the Upper Pliocene and Lower Pleistocene . The most important material, however, was found in the southeastern part of the USA . Outstanding are the Leisey Shell Pit in Hillsborough County of Florida as well as the Haile 16A site in Alachua County , also Florida. Both locations each contained several hundred osteoderms and armor remains, the latter also containing some elements of the musculoskeletal system. All finds are also placed on Pachyarmatherium . There are also individual other smaller sites such as the Kissimmee River in Okeechobee County in Florida, Apollo Beach, which is adjacent to the Leisey Shell Pit, and several pieces from Dorchester County in South Carolina . For all of the named sites there is an age classification in the Pliocene-Pleistocene transition area.

literature

  • Juan C. Fernicola, Andrés Rinderknecht, Washington Jones, Sergio F. Vizcaíno and Kleberson de Oliveira Porpino: A new species of Neoglyptatelus (Mammalia, Xenarthra, Cingulata) from the late Miocene of Uruguay provides new insights on the evolution of the dorsal armor in cingulates. Ameghiniana 55, 2018, pp. 233-252

Individual evidence

  1. ↑ In it A. Croft and Velizar Simeonovski: Horned armadillos and rafting monkeys. The fascinating fossil mammals of South America. Indiana University Press, 2016, pp. 1–304 (pp. 180–181)
  2. ↑ a b c d e f g Kevin F. Downing and Richard S. White: The cingulates (Xenarthra) of the Leisey Shell Pit local fauna (Irvingtonian), Hillborough County, Florida. Bulletin of the Florida Museum of Natural History 37 (Part II), 1995, pp. 375-396
  3. ↑ a b c d e f Kleberson de Oliveira Porpino, Juan C. Fernicola and Lílian P. Bergqvist: A New Cingulate (Mammalia: Xenarthra), Pachyarmatherium brasiliensesp. nov., from the Late Pleistocene of Northeastern Brazil. Journal of Vertebrate Paleontology 29 (3), 2009, pp. 881-893
  4. ↑ a b c d e f g h i j k Juan C. Fernicola, Andrés Rinderknecht, Washington Jones, Sergio F. Vizcaíno and Kleberson de Oliveira Porpino: A new species of Neoglyptatelus (Mammalia, Xenarthra, Cingulata) from the late Miocene of Uruguay provides new insights on the evolution of the dorsal armor in cingulates. Ameghiniana 55, 2018, pp. 233-252
  5. ↑ a b c d Édison Vicente Oliveira, Kleberson de Oliveira Porpino and Fabiana Marinho da Silva: New material of Pachyarmatherium from the late Pleistocene of northeastern Brazil: insights into its morphology and systematics. Paläontologische Zeitschrift 87, 2013, pp. 505–513, doi: 10.1007 / s12542-013-0166-4
  6. ^ A b Carlos Villarroel and Jairo Clavijo: Los mamíferos fósiles y las edades de las sedimentitas continentales del Neógeno de la Costa Caribe Colombiana. Revista de la Academia Colombiana de Ciencias 29 (112), 2005, pp. 345-356
  7. ↑ Paulo Victor Luiz Gomes Da Costa Pereira, Gustavo Duarte Victer, Kleberson de Oliveira Porpino and Lílian Paglarelli Bergqvist: Osteoderm histology of Late Pleistocene cingulates from the intertropical region of Brazil. Acta Palaeontologica Polonica 59 (3), 2014, pp. 543-552
  8. ↑ Rodrigo L. Tomassini, Claudia I. Montalvo and María C. Ezquiaga: The oldest record of flea / armadillos interaction as example of bioerosion on osteoderms from the late Miocene of the Argentine Pampas. International Journal of Paleopathology 15, 2016, pp. 65-68, doi: 10.1016 / j.ijpp.2016.08.004
  9. ↑ Fábio Cunha Guimarães de Lima and Kleberson de Oliveira Porpino: Ectoparasitism and infections in the exoskeletons of large fossil cingulates. PLoS ONE 13 (10), 2018, p. E0205656, doi: 10.1371 / journal.pone.0205656
  10. ↑ Maureen A. O'Leary, Jonathan I. Bloch, John J. Flynn, Timothy J. Gaudin, Andres Giallombardo, Norberto P. Giannini, Suzann L. Goldberg, Brian P. Kraatz, Zhe-Xi Luo, Jin Meng, Xijun Ni, Michael J. Novacek, Fernando A. Perini, Zachary S. Randall, Guillermo W. Rougier, Eric J. Sargis, Mary T. Silcox, Nancy B. Simmons, Michelle Spaulding, Paúl M. Velazco, Marcelo Weksler, John R Wible and Andrea L. Cirranello: The Placental Mammal Ancestor and the Post-K-Pg Radiation of Placentals. Science 339, 2013, pp. 662-667, doi: 10.1126 / science.1229237
  11. ↑ Kenneth D. Rose: The beginning of the age of mammals. Johns Hopkins University Press, Baltimore, 2006, pp. 1–431 (pp. 200–204)
  12. ^ Sergio F. Vizcaíno and WJ Loughry: Xenarthran biology: Past, present and future. In: Sergio F. Vizcaíno and WJ Loughry (eds.): The Biology of the Xenarthra. University Press of Florida, 2008, pp. 1-7
  13. ↑ Frédéric Delsuc, Michael J. Stanhope and Emmanuel JP Douzery: Molecular systematics of armadillos (Xenarthra, Dasypodidae): contribution of maximum likelihood and Bayesian analyzes of mitochondrial and nuclear genes. Molecular Phylogenetics and Evolution 28, 2003, pp. 261-275
  14. ↑ Frédéric Delsuc, Sergio F Vizcaíno and Emmanuel JP Douzery: Influence of Tertiary paleoenvironmental changes on the diversification of South American mammals: a relaxed molecular clock study within xenarthrans. BMC Evolutionary Biology 4 (11), 2004, pp. 1-13
  15. ↑ Timothy J. Gaudin and John R. Wible: The Phylogeny of Living and Extinct Armadillos (Mammalia, Xenarthra, Cingulata): A Craniodental Analysis. In: MT Carrano, TJ Gaudin, RW Blob and JR Wible (eds.): Amniote Paleobiology. Chicago / London: University of Chicago Press, 2006, pp. 153-198
  16. ↑ Guillaume Billet, Lionel Hautier, Christian de Muizon and Xavier Valentin: Oldest cingulate skulls provide congruence between morphological and molecular scenarios of armadillo evolution. Proceedings of the Royal Society B, 278, 2011, pp. 2791-2797
  17. ↑ Frédéric Delsuc, Gillian C. Gibb, Melanie Kuch, Guillaume Billet, Lionel Hautier, John Southon, Jean-Marie Rouillard, Juan Carlos Fernicola, Sergio F. Vizcaíno, Ross DE MacPhee and Hendrik N. Poinar: The phylogenetic affinities of the extinct glyptodonts. Current Biology 26, 2016, pp. R155-R156, doi: 10.1016 / j.cub.2016.01.039
  18. Jump up ↑ Kieren J. Mitchell, Agustin Scanferla, Esteban Soibelzon, Ricardo Bonini, Javier Ochoa and Alan Cooper: Ancient DNA from the extinct South American giant glyptodont Doedicurus sp. (Xenarthra: Glyptodontidae) reveals that glyptodonts evolved from Eocene armadillos. Molecular Ecology 25 (14), 2016, pp. 3499-3508, doi: 10.1111 / mec.13695
  19. ^ A b Alfredo A. Carlini, Sergio F. Vizcaíno and Gustavo J. Scillato-Yané: Armored xenarthrans: a unique taxonomic and ecologic assemblage. In: Richard F. Kay, Richard H. Madden, Richard L. Cifelli, and John J. Flynn (Eds.): Vertebrate Paleontology in the Neotropis. The Miocene fauna of La Venta, Colombia. Smithsonian Institution Press, Washington, 1997, pp. 213-226
  20. ↑ a b Sergio F. Vizcaíno, André S. Rinderknecht and Ada Czerwonogora: An enigmatic Cingulata (Mammal ia: Xenarthra) from the Late Miocene of Uruguay. Journal of Vertebrate Paleontology 23 (4), 2003, pp. 981-983
  21. ↑ a b César Laurito Mora, Ana Lucía Valerio Zamora and Eduardo Antonio Pérez Gamboa: Los xenarthras fósiles de la localidad de Buenos Aires de Palmares (Blancano tardío-Irvingtoniano temprano), provincia de Alajuela, Costa Rica. Revista Geológica de América Central 33, 2005, pp. 83-90
  22. ↑ a b Édison Vicente Oliveira, Alcina M. Franca Barreto and Rosemberg da Silva Alves: Aspectos sistemáticos, paleobiogeográficos e paleoclimáticos dos mamíferos quaternários de Fazenda Nova, PE, nordeste do Brasil. Gaea Journal of Geoscience 5, 2009, pp. 75-85
  23. ^ Mario Alberto Cozzuol: The Acre vertebrate fauna: Age, diversity, and geography. Journal of South American Earth Sciences 21, 2006, pp. 185-203
  24. ↑ Ascanio D. Rincón, Gilberto E. Parra, Francisco J. Prevosti, Maria Teresa Alberdi and Christopher J. Bell: A preliminary assessment of the mammalian fauna from the Pliocene-Pleistocene El Breal de Orocual locality, Monagas State, Venezuela. Museum of Northern Arizona Bulletin 65, 2009, pp. 593-620
  25. ^ Andrés Solórzano, Ascanio D. Rincón and H. Gregory McDonald: A New Mammal Assemblage from the Late Pleistocene El Breal de Orocual, Northeast of Venezuela. Science Series 42, 2015, pp. 125-150
  26. ^ Ascanio D. Rincón and Richard White: Los Xenarthra Cingulata del Pleistoceno tardío (Lujanense) de Cerro Misión, Estado Falcón, Venezuela. Boletín de la Sociedad Venezolana de Espeleología 41, 2007, pp. 2-12
  27. ^ Jean-Noël Martinez and Ascanio Daniel Rincón: Los Xenarthra Cingulata del noroeste del Perú. Resúmenes extendidos del XV Congreso Peruano de Geología, Publicación Especial de la Sociedad Geológica del Perú, Actas 9, 2010, pp. 432-435
  28. ^ Ana L. Valerio and César A. Laurito: Nuevos hallazgos de Mammalia, Xenarthra (Cingulata) y confirmación del registro de Pachyarmatherium leiseyi Downing & White, 1995 en la localidad de Buenos Aires de Palmares, provincia de Alajuela, Costa Rica. Revista Geológica de América Central 44, 1911, pp. 131-139
  29. ^ César A. Laurito and Ana L. Valerio: Paleobiogeografía del arribo de mamíferos suramericanos al sur de América Central de previo al Gran Intercambio Biótico Americano: un vistazo al GABI en América Central. Revista Geológica de América Central 46, 2012, pp. 123-144

Web links

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