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Feeding giant anteaters and tamanduas as insectivorous species provides a lot of challenges for zoological institutions. In the last decades an in‐house mixture, called 'Dortmund mixture', was the most common feed used in giant anteaters and tamanduas in many countries within the European Association of Zoos and Aquaria ex‐situ Programme (EEP). Some nutritional problems occurred due to imbalances in the diets. The more recent nutritional recommendations for both species advise an adapted and balanced complete feed formulated for insectivorous species due to different problems arising with an in‐house mixed feed as Dortmund mixture. To objectify the present situation a questionnaire was designed and sent out to 78 institutions of the EEPs for giant anteater(s) and tamandua(s). The questionnaire was divided into different sections and asked for data on husbandry, health status, feeding, especially feed composition, feed supplementation and faecal consistency. It was completed by 45 institutions with data for 130 animals, 89 giant anteaters and 41 tamanduas. The data thus represent 54% and 59% of the EEP populations. For both species, a complete feed is mainly utilised. Especially institutions that have integrated anteaters and tamanduas into their facilities during the last 10 and 20 years, use a complete feed. Regarding the in‐house mixtures, there are distinct differences, both in composition and amount of each ingredient used. The evaluation of the feeds used for enrichment, for example, shows a clear species difference. While in tamanduas mainly insects are used for this purpose, in giant anteaters it is mainly fruits and avocado. In contrast to the past, many anteaters today are fed an adapted complete feed. Surprisingly, concerning feeding supplements the use of fat‐soluble vitamins and combined vitamin–mineral preparations is still common in both species. More effort needs to be put into enforcing current feeding recommendations, especially for the giant anteaters. [ABSTRACT FROM AUTHOR]

El hormiguero palmero Myrmecophaga tridactyla es una especie que se encuentra amenazada en la Orinoquía, por la fragmentación del paisaje, el atropellamiento en las vías, los monocultivos de arroz, la palma africana y la actividad de extracción de petróleo. El atropellamiento de animales en las redes viales disminuye la tasa de supervivencia anual de los hormigueros, reduciendo la tasa de crecimiento de la especie a valores nulos, como se observa en algunas áreas. Por otro lado, los animales enfermos o atropellados requieren diagnóstico o tratamiento para recuperar su salud, por lo tanto, el propósito del trabajo fue conocer la hematología y la bioquímica sérica en animales silvestres, aparentemente sanos, rescatados por Cormacarena. Previa restricción y sedación con Zoletil® 50, a la dosis de 4 mg/k de peso vivo, se practicó examen clínico y se recolectó de 5-10 mL de sangre por venopunción, a 21 animales. Posterior a su recuperación se liberaron los individuos. Se presentan los valores hematológicos de referencia para eritrocitos, hemoglobina, hematocrito, plaquetas, leucocitos, neutrófilos, linfocitos, proteínas totales, ALT, AST, BUN, creatinina, calcio, fósforo, potasio, sodio, los cuales, son de importancia en la valoración médico-veterinaria, en los programas de conservación de la especie. Se resalta que los valores en osos palmeros de la región son similares a los descritos en otros trabajos en América.

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This study aimed to describe the brain base arteries of the Myrmecophaga tridactyla using ten cadavers of adults from this species, including five male and five female specimens. The arterial vascular bed was perfused via the thoracic aorta with a dyed natural latex solution, and the animals were fixed and preserved with a 10% formaldehyde buffered solution. The encephala were removed, and their vessels dissected. Basilar artery formation occurred by anastomosis of the thick ventral spinal artery with vertebral arteries. The basilar artery formed two arterial islands and gave bulbar and pontine branches, and cranial, middle, and caudal cerebellar arteries and ended by forking into its terminal branches, the caudal communicating arteries. The blood supply of the encephalon derived solely from the vertebrobasilar system, and the arterial circle of the brain was closed caudally and rostrally. The absence of participation of internal carotid arteries in encephalon irrigation, the island formations by the basilar artery, and the fusiform shape of the arterial circle of the brain are peculiar characteristics of the vascular anatomy of the brain base of M. tridactyla. [ABSTRACT FROM AUTHOR]

This study aimed to describe the brain base arteries of the Myrmecophaga tridactyla using ten cadavers of adults from this species, including five male and five female specimens. The arterial vascular bed was perfused via the thoracic aorta with a dyed natural latex solution, and the animals were fixed and preserved with a 10% formaldehyde buffered solution. The encephala were removed, and their vessels dissected. Basilar artery formation occurred by anastomosis of the thick ventral spinal artery with vertebral arteries. The basilar artery formed two arterial islands and gave bulbar and pontine branches, and cranial, middle, and caudal cerebellar arteries and ended by forking into its terminal branches, the caudal communicating arteries. The blood supply of the encephalon derived solely from the vertebrobasilar system, and the arterial circle of the brain was closed caudally and rostrally. The absence of participation of internal carotid arteries in encephalon irrigation, the island formations by the basilar artery, and the fusiform shape of the arterial circle of the brain are peculiar characteristics of the vascular anatomy of the brain base of M. tridactyla.

The giant anteater (Myrmecophaga tridactyla) is a member of the Myrmecophagidae family and is now classified as ''Vulnerable'' due to the risk of extinction. In spite of this, research on reproductive biotechnologies in the species is rare, and semen collection has only been performed using electroejaculation to date. Pharmaceutical semen collection through urethral catheterization has become a distinct method that is being applied to numerous species of wild animals. In addition to establishing a species-specific setup, we compared semen acquired by urethral catheterization in three wild animals to that obtained in captivity in two animals. The average volume of semen collected was 180,0 ± 24.5 µL, with an average motility of 62 ± 14.7% and a vigor of 3,9 ± 0.8. The concentration of sperm was 194.6 ± 139.8 × 106 per mL. Using pharmaceutical semen collection through urethral catheterization was an effective, practical, and safe way for semen collection and evaluation in captive and free-living giant anteaters, according to the compiled data. We have described a specific setup for analyzing giant anteater semen using the CASA system, eliminating subjectivity from future research.

Los Xenarthra son un grupo de mamíferos, de gran importancia histórica y ecológica, originados en Suramérica. La implementación de técnicas en genética molecular en estos animales está en aumento y para ello, losmétodos de muestreo mínimamente invasivos son una herramienta exitosa para el monitoreo genético. Enesta investigación se comparó la calidad y cantidad de ADN obtenido de sangre, tejidos, saliva, pelos y heces,usando dos kits comerciales: PrepFiler™ y GeneJET™. La concentración, pureza e integridad del ADN fueronevaluadas usando espectrofotometría y electroforesis. Se usó una ANOVA de dos factores mezclados y unaprueba de comparaciones múltiples de Tukey para comparar los diferentes métodos de extracción de ADN ya través de las diferentes muestras biológicas. El mayor rendimiento de ADN fue obtenido para las muestrasde tejido con el kit PrepFiler™, con una concentración media de 5,25 ng/μL, una pureza de 1,87 y una bandadefinida en la electroforesis. Sin embargo, no recomendamos el uso de estas muestras en animales vivos.El ADN obtenido de saliva con el kit PrepFiler™ ofreció resultados similares en términos de concentración(media 3,56 ng/μL), pureza de 1,85 e integridad; además, la prueba de comparación de Tukey mostró queno hay diferencias entre las muestras de saliva y sangre (p= 0,01028); la obtención de muestras de salivarequiere menos intervención en los animales. Por esta razón, se concluye que la extracción de ADN usandoel kit PrepFiler™ en muestras de saliva es la mejor opción para extracción de ADN de calidad en las especies estudiadas.

Tamandua mexicana se distribuye desde México hasta el norte de América del Sur, con escasos registros en sistemas insulares. En esta nota presentamos un registro de la especie en Isla del Carmen, Golfo de México. El 13 de febrero de 2021 observamos casualmente un adulto muerto sobre la carretera federal 180, en la parte noreste de la isla. Este registro contribuye al conocimiento de la distribución de T. mexicana en México, país donde este mamífero se encuentra actualmente en peligro de extinción. Se sugiere realizar un estudio para conocer si presenta una población estable en dicha isla o su presencia en ella es ocasional por el posible arribo de individuos procedentes de áreas continentales más próximas a la misma.

A case of melanism in Tamandua tetradactyla (Myrmecophagidae) is recorded, based on an individual observed in the Huánuco Department, Peru. Two previous records are found in the iNaturalist database. With this record, the number of melanistic mammal species in Peru increases to four. It should be noted that cases of melanism in this species have already been reported in the Neotropics.

Copyright of Actualidades Biológicas is the property of Universidad de Antioquia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT This work aimed to describe the origin, distribution, and ramifications of the ischiadicus nerve in the giant anteater and to provide anatomical data which could explain not only the evolutionary aspects but also provide important information for other related works. For the present study, four specimens were used, prepared by perfusion of 10% formaldehyde solution via the femoral artery, for conservation and dissection. The origin of the right and left ischiadicus nerves in the giant anteater from the ventral ramification of the third lumbar (L3) and the first (S1), second (S2), and third (S3) sacral spinal nerves. These nerves were symmetrical in all animals studied. The distribution and ramification occurred to the superficial, middle, and deep gluteal, gemelli, piriform, quadratus femoris, tensor fasciae latae, caudal crural abductor, cranial and caudal parts of the biceps femoris, adductor, semitendinous, and cranial and caudal parts of the semimembranous muscles. Based on the origins of the ischiadicus nerves, there is a caudal migration in the nerve location in animals in a more recent position on the evolutionary scale due to reconfiguration of the lumbosacral plexus, resulting from the increase in a number of lumbar vertebrae. There is no complete homology of the muscle innervation.

Abstract Background The southern tamandua, Tamandua tetradactyla (Linnaeus, 1758), is the most common species of anteater. Even though much is known about its ecology, behavior, and parasites, there is very limited information about bone diseases in Tamandua and other anteaters. Here, we examined postcranial skeletons of 64 T. tetradactyla museum specimens covering most of the material available in Brazilian collections. Results The following bone diseases were identified for the first time in Tamandua and other extant and fossil vermilinguans: osteophytes, osteitis, osteoarthritis, periostitis, exostoses, enthesopathies, and a severe chronic pyogenic osteomyelitis associated with fistulae, cloacae (pus), bone loss, and neoformation processes. Musculoskeletal reconstruction revealed that an old specimen was restricted to terrestrial locomotion due to osteopathological processes that impaired its climbing. Conclusions New osteopathological informations are presented for T. tetradactyla, favoring a better understanding of the expression of some bone diseases in wild animals. In addition, the diagnosis of these bone diseases in living anteaters provides useful information for studies on animal health and welfare, as well as contributing to the more effective recognition of paleodiseases in fossil xenarthrans.

Zoological parks are an excellent source of biological material for research, as they often receive free-living wild animals. The present report discusses the occurrence of mites in the ear canal in a free-living anteater in the Metropolitan Region of Sorocaba, forwarded to the Sorocaba Zoo. During the clinical examination of the animal ectoparasites were located and collected. The mites were collected from the ear canal and were deposited in plastic pots with 70% alcohol, then sent to the National Reference Laboratory for Rickettsial Diseases Vectors (LIRN) of the Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation (FIOCRUZ). Using taxonomic specific keys and with the aid of a microscope, the species Psoralges libertus Trouessart, 1896 was morphologically identified. This species was reported in another species from the Order Pilosa, but it is the first record of Psoralges libertus parasitizing a free-living Myrmecophaga tridactyla Linnaeus, 1758. [ABSTRACT FROM AUTHOR]

Abstract Amblyomma nodosum is a Neotropical tick species distributed from Mexico to Argentina, with adult individuals infesting different mammal species, including anteaters (Pilosa: Myrmecophagidae). Few reports in Colombia have recorded this species in departments such as Meta, Tolima and Valle del Cauca. In this paper we describe this species using taxonomic, morphometric and molecular methods after collecting individuals parasitizing collared anteaters (Tamandua tetradactyla) in the departments of Cundinamarca and Tolima. Adult specimens were identified based on current taxonomic keys and different morphometric variables were documented in nonengorged individuals. Also, DNA was extracted for PCR amplification and sequencing of 16S rDNA, COI and ITS2 genes. Phylogenetic trees were built. One hundred and thirty-four adult ticks were collected and identified as Amblyomma nodosum, based on morphological, morphometric, molecular and phylogenetic analyses. This is the first study to report the presence of this tick species in the department of Cundinamarca, using multiple identification approaches, thus expanding its geographical records in Colombia.

Copyright of Acta Veterinaria Brasilica is the property of Acta Veterinaria Brasilica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

O objetivo deste estudo foi descrever a distribuição dos nervos do membro pélvico do T. tetradactyla. Para tanto, foram utilizados quatro cadáveres de animais adultos cedidos pelo IBAMA-GO. Cada animal teve o membro pélvico de ambos os antímeros dissecados após fixação em solução de formaldeído a 10%. Os nervos genitofemoral e cutâneo femoral lateral distribuíram-se na pele medial e craniomedial e craniolateral da coxa, respectivamente. O nervo femoral emitiu ramos para os músculos psoas menor, iliopsoas, sartório e pectíneo; terminando por penetrar no músculo quadríceps femoral. Emitiu o nervo safeno, que em seu trajeto, inervou a pele da face medial da coxa e perna e região dorsomedial do pé. O nervo obturador emitiu ramos para músculos mediais da coxa. Os nervos glúteos cranial e caudal inervaram a musculatura glútea. O nervo isquiático inervou os músculos gêmeos, quadrado femoral, semi-membranoso, semitendinoso, bíceps femoral longo e curto e terminou dividindo-se nos nervos cutâneo lateral da sura, tibial, e fibular comum. O nervo cutâneo lateral da sura inerva a região cutânea craniolateral do joelho e perna, enquanto os nervos fibular comum e tibial inerva a musculatura da perna e terminam distribuindo-se no pé.

Pelage patterns, colouration and other biometric traits are perceived to be uniform in the Neotropical giant anteater (Myrmecophaga tridactyla), a conception precluding the identification of individuals, which is essential for field research on the little known aspects of the species’ ecology and behaviour. Here we present a new, non-invasive technique of matrix photo-identification to identify individual giant anteaters by their natural markings. In a long-term field study in the Brazilian Pantanal, photographs of 475 giant anteater observations (396 = direct sightings, 79 = camera traps) were captured from 2010 to 2015 and considered for our analysis. Photographs were stored in a catalogue and coded in a computerised identification table, with biometric traits being categorised and described for each observed individual in a matrix. In 71% of all photographed giant anteaters, differences in pelage marking patterns, as well as other characteristics such as ear shape and scars, allowed individual recognition. We ensured consistency of the method by conducting a double-blind verification by an experienced researcher and naïve volunteers. This simple, non-invasive method can push the level of information about life history and population structure of giant anteaters, as it applies to a large array of study designs. It can thus enhance future studies, be integrated in ongoing research projects or supply additional information out of older data sets. It is applicable to expand data collection and raise awareness in local communities, and potentially for participatory citizen science methods. Altogether these are important cornerstones for conservation actions on the species which is listed as ‘Vulnerable’ on the International Union for Conservation of Nature Red List of Threatened Species. [ABSTRACT FROM AUTHOR]

Pterygodermatites is a cosmopolitan genus of nematodes from mammals, and it is frequently encountered in the parasite fauna of armadillos (Mammalia, Xenarthra, Cingulata). In this work, a new species, Pterygodermatites ( Paucipectines) argentinensis, is described, and new morphometric data, new host records, and the geographical distribution of Pterygodermatites ( Paucipectines) chaetophracti are provided. We examined 109 hosts belonging to Chaetophractus vellerosus, Chaetophractus villosus, Cabassous chacoensis, Dasypus hybridus, Tolypeutes matacus, and Zaedyus pichiy, from several regions of Argentina. Pterygodermatites ( Paucipectines) argentinensis can be distinguished from P. ( P.) chaetophracti by the morphology and size of esophageal teeth of both sexes, by subequal and longer spicules, by having only 1 precloacal cuticular semicircular fan in males, and by a greater number of cuticular processes in females. Cabassous chacoensis and Zaedyus pichiy are new hosts for Pterygodermatites ( P.) chaetophracti. [ABSTRACT FROM AUTHOR]

The distribution of the giant anteater (Myrmecophaga tridactyla Linnaeus, 1758) is poorly known, especially outside Brazil. Here, we present an approx. 430-km range expansion for the species based on 71 records collected from interviews, camera traps, tracks, and direct sightings in the Magdalena-Urabá moist forest ecoregion (MUMFE), Colombia. Our records, obtained from 31 localities during July 2013 to July 2015, represent the first evidence of M. tridactyla in the middle Magdalena River valley since the late 18th Century. Our camera traps identified at least six individual giant anteaters, including a female with offspring. We discuss the severity of threats in the MUMFE and the urgency for conservation planning. [ABSTRACT FROM AUTHOR]

The aim of this study was to describe the distribution of the pelvic limb nerves of T. tetradactyla. With this purpose, five adult cadavers provided by IBAMA-GO were used. Each animal had the pelvic limb of both antimeres dissected after fixation in a 10% formaldehyde solution. The genitofemoral and lateral femoral cutaneous nerves are distributed in the medial, craniomedial and craniolateral skin of the thigh, respectively. The femoral nerve sent branches to the psoas minor, iliopsoas, sartorius and pectineus muscles, and terminated penetrating the quadriceps femoris muscle. It also gave rise to the saphenous nerve, which in its trajectory it innervated the skin of the medial aspect of the thigh, leg and the dorsomedial region of the foot. The obturator nerve sent branches to the medial thigh muscles. The cranial and caudal gluteal nerves innervated the gluteal muscles. The sciatic nerve innervated gemeli, quadratus femoris, semimembranosus, semitendinosus, long and short biceps femoris muscles and ended up dividing into lateral sural cutaneous, tibial and common fibular nerves. The lateral sural cutaneous nerve innervated the craniolateral skin of the knee and leg, while the common fibular and tibial nerves innervated the muscles of the leg and ended up distributing in the foot. [ABSTRACT FROM AUTHOR]

Anteaters belong to the Order Xenarthra / Family Myrmecophagidae and are the only members without teeth. There are three genera with four living species in the family Myrmecophagidae: Myrmecophaga tridactyla (giant anteater), Tamandua tetradactyla (southern lesser anteater), Tamandua mexicana (northern lesser anteater), and Cyclopes didactylus (silky anteater). The karyotypes of M. tridactyla (2n = 60), T. tetradactyla (2n = 54) and C. didactylus (2n = 64) have already been described. In the present paper, three female and two male specimens of giant anteater and one lesser anteater male were analyzed. The results indicate the existence of a new karyotype in the genus Tamandua, with 2n = 56 chromosomes, which can represent a new lesser anteater species. The karyotype of M. tridactyla was also described, supporting previous reports.

The giant anteater ( Myrmecophaga tridactyla ) is considered vulnerable to extinction. Scientific data on the reproductive parameters of this species are scarce. Semen from eight free-ranging giant anteaters was collected to establish its characteristics and the effects of cooling and storage at 5 °C after dilution with the BotuCrio extender without cryoprotectant. The ejaculate presented two distinct sequential fractions, including a whitish fraction, which was milky and rich in sperm cells, and a gel fraction, which was colorless, viscous, and azoospermic. The mean ± standard error of the mean values of the seminal characteristics were as follows: volume of the first fraction, 0.75 ± 0.1 mL; motility, 75 ± 2.9%; vigor, 3.2 ± 0.3; sperm motility index, 68.8 ± 4.3; concentration, 108.5 ± 13.4 × 10 6 /mL; plasma membrane integrity index, 71 ± 4.0%; spermatic defects detected using modified Karras staining, 35.5 ± 3.3%; and spermatic alterations identified by differential interference contrast microscopy, 48.3 ± 6.8%. During refrigeration, the semen presented decreasing motility from 0 to 18 hours, sperm motility index decreased from 0 to 24 hours, and vigor did not change in the first 6 hours and then decreased to 18 hours. [ABSTRACT FROM AUTHOR]

The anatomy and histology of the male genital tract of the lesser anteater were studied. Fine details of spermatozoa regarding their genesis and morphology were also studied in six adult specimens. The testes lie in the pelvic cavity. The deferent duct emerges from the epididymis and opens into the ejaculatory duct, which drains into the membranous urethra. Accessory glands (prostate, seminal vesicle and bulbourethral gland) are histologically similar to those described in other mammals. The short penis presents an urethral orifice, while the corpus spongiosum becomes thinner at the end indicating the absence of a histologically defined glans. The seminiferous epithelium shows: (1) Sertoli cells with deep nuclear indentations, (2) spermatogonia with crusty-like chromatin, (3) spermatocytes at different stages of maturation and (4) three morphologically distinct stages of spermatid differentiation according to nuclear shape, acrosome development and chromatin condensation. Sperm heads appear oval. The length of the spermatozoa averages 67.33 ± 1.60 μm. Two specimens with inactive spermatogenesis were azoospermic. Their testes and epididymis presented sizes smaller than those with active spermatogenesis. These studies together with others in anteaters may contribute to successful breeding in conservation programmes. [ABSTRACT FROM AUTHOR]

Phintella piatensis is an unusual jumping spider because, despite being neither myrmecophagic nor myrmecomorphic, it associates with ants, including dangerous weaver ants. Although salticids typically spin cocoon-like nests for use as shelters, the nests of Phintella are unusually dense. These play an important role in how Phintella adapts to living with ants. In experiments, intraspecific interaction and mating increased the risk of being killed by ants when there was no accessible nest, while access to a nest eliminated this risk. Additionally, while outside nests, seeing ants made Phintella reluctant to mate, this being an unusual example of a small animal with exceptional eyesight compensating for predation risk when making vision-based mating decisions. On the whole, the behaviour of Phintella during intraspecific interaction had broad similarity to the pattern that is common in salticids, but with some of the details of courtship suggesting further adaptation to interacting in the presence of dangerous ants. [ABSTRACT FROM AUTHOR]

Members of the family Myrmecophagidae (i.e. anteaters) show a variety of anatomical and behavioural adaptations to deal with their low-energy diet; for example, they all have low body temperatures in comparison with other eutherian mammals. In this study, we investigated the tympanic membrane temperatures ( Tmt) of two giant anteaters and three southern tamanduas, housed in captivity and exposed to natural climatic variations in temperature, using an infrared thermometer. Additionally, we measured external dorsal temperature ( Td), air temperature ( Ta), substrate temperature ( Ts) and whether the subject was active or not. To understand the effect of time of day on these variables, we recorded them, on the hour, over four 24-h cycles for each animal during which the subjects were non-restrained within their enclosures. The results show that both giant anteaters and southern tamanduas allow their Tmt to reduce between 4.0 and 6.5 °C when they are sleeping. Furthermore, linear regressions between Tmt and Ta or Ts showed that the giant anteaters were much more affected by Ta and Ts than the southern tamanduas. Both species also showed higher Tmt when active (comparing subjects active and inactive at the same Ta). Both species appear to use shallow torpor during a normal 24-h cycle probably as a means to economize energy. The torpor in giant anteaters occurred during the night when asleep, whereas in the southern tamanduas it occurred at any time of day when asleep. The giant anteaters appeared to be more directly affected by environmental temperature than the southern tamanduas. [ABSTRACT FROM AUTHOR]

Abstract: Recent rapid generation of genomic sequence data has allowed many researchers to perform comparative analyses in various mammalian species. However, characterization of transposable elements, such as short interspersed repetitive elements (SINEs), has not been reported for several mammalian groups. Because SINEs occupy a large portion of the mammalian genome, they are believed to have contributed to the constitution and diversification of the host genomes during evolution. In the present study, we characterized a novel SINE family in the anteater genomes and designated it the MyrSINE family. Typical SINEs consist of a tRNA-related, a tRNA-unrelated and an AT-rich (or poly-A) region. MyrSINEs have only tRNA-related and poly-A regions; they are included in a group called t-SINE. The tRNA-related regions of the MyrSINEs were found to be derived from tRNAGly. We demonstrate that the MyrSINE family can be classified into three subfamilies. Two of the MyrSINE subfamilies are distributed in the genomes of both giant anteater and tamandua, while the other is present only in the giant anteater. We discuss the evolutionary history of MyrSINEs and their relationship to the evolution of anteaters. We also speculate that the simple structure of t-SINEs may be a potential evolutionary source for the generation of the typical SINE structure. [Copyright &y& Elsevier]

The purpose of this study was to correlate the activity and habitat use of a large and ecologically specialized mammal ( Myrmecophaga tridactyla) with the time of day and minimum daily temperature in Brazil's Pantanal wetland. Seven giant anteaters were fitted with very high frequency (VHF) radio transmitters and monitored from March to December 2001. The animal's state of activity or rest, time and ambient temperature were recorded in different patches of the study site, which were covered by a mosaic of vegetation types and several ponds. Whenever a giant anteater was inside a forest patch, the temperature inside and outside of the patch was also recorded. The temperatures throughout the day were recorded by the meteorological station at the study site. The period of greatest activity of giant anteaters started at 18:00 h on hot days, but whenever the daily minimum temperature declined, the species' activity began earlier. Giant anteaters use predominantly forest habitats for rest and open habitats for activity. The forest patches work as a temperature buffer, because they are cooler than the matrix of open habitats during the hot hours of the day and warmer than the matrix during the cold hours. Although the giant anteater is known to be associated with open habitats, this study indicates the need of preserving forest patches for the conservation of this species. [ABSTRACT FROM AUTHOR]

Appeals to synapomorphic features of the wrist and hand in African apes, early hominins, and modern humans as evidence of knuckle-walking ancestry for the hominin lineage rely on accurate interpretations of those features as adaptations to knuckle-walking locomotion. Because Gorilla, Pan, and Homo share a relatively close common ancestor, the interpretation of such features is confounded somewhat by phylogeny. The study presented here examines the evolution of a similar locomotor regime in New World anteaters (order Xenarthra, family Myrmecophagidae) and uses the terrestrial giant anteater (Myrmecophaga tridactyla) as a convergence test of adaptation for purported knuckle-walking features of the Hominidae. During the stance phase of locomotion, Myrmecophaga transmits loads through flexed digits and a vertical manus, with hyperextension occurring at the metacarpophalangeal joints of the weight-bearing rays. This differs from the locomotion of smaller, arboreal anteaters of outgroup genera Tamandua and Cyclopes that employ extended wrist postures during above-branch quadrupedality. A number of features shared by Myrmecophaga and Pan and Gorilla facilitate load transmission or limit extension, thereby stabilizing the wrist and hand during knuckle-walking, and distinguish these taxa from their respective outgroups. These traits are a distally extended dorsal ridge of the distal radius, proximal expansion of the nonarticular surface of the dorsal capitate, a pronounced articular ridge on the dorsal aspects of the load-bearing metacarpal heads, and metacarpal heads that are wider dorsally than volarly. Only the proximal expansion of the nonarticular area of the dorsal capitate distinguishes knuckle-walkers from digitigrade cercopithecids, but features shared with digitigrade primates might be adaptive to the use of a vertical manus of some sort in the stance phase of terrestrial locomotion. The appearance of capitals nonarticular expansion and the dorsal ridge of the distal radius in the hominin lineage might be indicative of a knuckle-walking ancestry for bipedal hominins if interpreted within the biomechanical and phylogenetic context of hominid locomotor evolution. [ABSTRACT FROM AUTHOR]