High frequency of pauses during intermittent locomotion of small South American gymnophthalmid lizards (Squamata, Gymnophthalmidae)

We studied the locomotor behavior of two closely-related species of Gymnophthalmini lizards, Vanzosaura rubricauda and Procellosaurinus tetradactylus, that was imaged under laboratory conditions at a rate of 250 frames/s with a high-speed video camera (MotionScope PCI 1000) on four different substrates with increasing degrees of roughness (smooth perspex, cardboard, glued sand, and glued gravel). Vanzosaura rubricauda and P. tetradactylus are both characterized by intermittent locomotion, with pauses occurring with high frequency and having a short duration (from 1/10 to 1/3 s), and taking place in rhythmic locomotion in an organized fashion during all types of gaits and on different substrates. The observed variations in duration and frequency of pauses suggest that in V. rubricauda mean pause duration is shorter and pause frequency is higher than in P. tetradactylus. The intermittent locomotion observed in V. rubricauda and P. tetradactylus imaging at 250 frames/s is probably of interest for neurobiologists. In the review of possible determinants, the phylogenetic relationships among the species of the tribe Gymnophthalmini are focused

Systematic revision of the Phorusrhacidae (Aves: Ralliformes)

Fossil remains of birds belonging to the family Phorusrhacidae were studied in several museums of South America, North America and Europe, the main objective being to characterize this family and solve the chaotic state of the nomenclature and classification of these birds. Reconstruction of some species has been done, with the purpose of having an idea about the size, body weight, posture and habit based in their skeletons. The European species, Ameghinornis minor and Aenigmavis sapea are refuted as belonging to this family. Also several forms described from the Tertiary of Argentina are refuted, because they are based on inadequate segments of the skeleton for a good identification, as is the case of the genera Cunampaia, Smiliornis, Pseudolarus, Lophiornis and Riacama, frequently refered to as belonging to the Phorusrhacidae. The Phorusrhacidae family probably originated in South America, since the end of the Cretaceous, as a result of an endemism formed by the isolation of this landmass. During the end of the Pliocene, with the emersion of the Panama isthmus, the family spread to the North America where at least one species is known Titanis walleri, which perhaps represents the last known species of this family, probably becoming extinct in the beginning of the Pleistocene. A systematic revision has been conducted, dealing with the countless problems of nomenclature, and the Phorusrhacidae is now composed of five subfamilies, which are: Brontornithinae, Phorusrhacinae, Patagornithinae, Psilopterinae and Mesembriornithinae in which 13 genera and 17 species are considered. Characters of all taxa are described and a geochronological distribution of all species is presented.Foram estudados os fósseis de aves atribuídos à família Phorusrhacidae depositados em diversos museus da América do Sul, da América do Norte e da Europa, com o objetivo principal de caracterizar esta família e reorganizar o estado caótico que até então envolvia a nomenclatura e classificação destas aves. A reconstituição de algumas espécies é feita, com o propósito de formar uma idéia sobre o tamanho, massa corpórea, postura e hábitos com base no esqueleto das mesmas. As formas européias, Ameghinornis minor e Aenigmavis sapea são refutadas como pertencentes à esta família. São refutadas ainda várias formas do Terciário da Argentina, descritas com base em segmentos de esqueleto, insuficientes para uma plena identificação como é o caso dos gêneros Cunampaia, Smiliornis, Pseudolarus, Lophiornis e Riacama, freqüentemente referidos como pertencentes aos Phorusrhacidae. A família Phorusrhacidae certamente originou-se na América do Sul pelo final do Cretáceo, como resultado de um endemismo formado pelo isolamento dessa porção de terra. Pelo final do Plioceno, com a emersão do istmo do Panamá, a família estendeu-se até a América do Norte onde pelo menos uma espécie, Titanis walleri que talvez represente a última conhecida desta família, que extinguiu-se no início do Pleistoceno. A revisão sistemática foi conduzida com inúmeros problemas de nomenclatura e a família Phorusrhacidae passa então a ser constituída de cinco subfamílias, ou seja: Brontornithinae, Phorusrhacinae, Patagornithinae, Psilopterinae e Mesembriornithinae, nas quais se distribuem 13 gêneros e 17 espécies. Os caracteres de todos os táxons são descritos e finalmente é apresentada uma distribuição geocronológica de todas as espécies

Anatomia da Siringe dos Dendrocolaptidae (Aves, Passeriformes)

The syrinx is the vocal organ of the birds and it corresponds to a modification of the apparatus respiratorius, being at most of the cases, localized at the caudal end of the trachea and the cranial portion of the bronchi. The main purpose of this paper is to describe the syrinx anatomy of the Dendrocolaptidae, with the analysis of 11 from the 13 genera accepted to this family. Besides the two series of cartilaginous elements (“A” and “B”) previously recognized, we adopted a third series of elements designated as “T” elements, which correspond to those cranial to the Membrana tracheosyringealis. The structural variation of the Dendrocolaptidae syrinx is considered small when compared with other well known suboscine taxa, such as the Pipridae. We found out intra-group diagnostic characters, as well as some phylogenetically informative characters. Contrary to the current knowledge, the woodcreeper’s syrinx is dorsoventrally assimetric, a characteristic that should be taken into account in future studies of other suboscine groups, especially in the case of using syringeal anatomy for systematic studies.A siringe é o órgão vocal das aves e corresponde a uma região modificada do tubo respiratório, que na maioria dos grupos situa-se na região caudal da traquéia e cranial dos brônquios. O objetivo principal deste trabalho é a descrição anatômica da siringe dos Dendrocolaptidae e, para tal, foram examinados representantes de 11 dos 13 gêneros aceitos nesta família. Além das duas séries de elementos (“A” e “B”) previamente reconhecidas, modificou-se a nomenclatura criando uma terceira série de elementos esqueléticos designados como elementos “T”, que correspondem àqueles craniais à membrana traqueossiringeal. A variação estrutural da siringe dos Dendrocolaptidae foi considerada pequena, quando comparada à variação observada em outros grupos de Suboscines, como os Pipridae. Há caracteres diagnósticos de alguns dos táxons estudados, assim como caracteres informativos do ponto de vista filogenético. Ao contrário do que pressupunha a literatura, a siringe dos arapaçus é assimétrica dorsoventralmente, característica que deverá, daqui para frente, ser levada em conta no estudo de outros táxons Suboscines, principalmente no caso de aplicação sistemática de caracteres siringeais

Effects of Surface Roughness on the Locomotion of a Long-Tailed Lizard, Colobodactylus taunayi

We analyzed the locomotor behavior of a long-tailed, forest floor, and leaf litter lizard, Colobodactylus taunayi, a species that retains the generalized Gymnophthalmidae Bauplan whilst presenting the discrete toe reduction associated with the Bachia-like pattern of limb reduction. We videotaped individuals moving on four substrates with increasing degrees of roughness: plastic, wooden board, glued sand, and glued gravel. Significantly higher speeds occurred on the last two substrates. As with most other limbed animals, increased speed was significantly correlated with simultaneous increases in both stride length and stride frequency. Independently of the kind of substrate, C. taunayi used rather slow lateral sequence walking trots. In contrast to other ectothermic tetrapods, and especially other Gymnophthalmidae, this species lacked perceptible lateral flexion of either the trunk or the tail to effectuate these slow gaits

Com o diabo no corpo: os terríveis papagaios do Brasil colônia

Desde a Antiguidade, papagaios, periquitos e afins (Psittacidae) fascinaram os europeus por seu vivo colorido e uma notável capacidade de interação com seres humanos. A descoberta do Novo Mundo nada faria além de acrescentar novos elementos ao tráfico de animais exóticos há muito estabelecido pelos europeus com a África e o Oriente. Sem possuir grandes mamíferos, a América tropical participaria desse comércio com o que tinha de mais atrativo, essencialmente felinos, primatas e aves - em particular os papagaios, os quais eram embarcados em bom número. Contudo, a julgar pelos documentos do Brasil colônia, esses voláteis podiam inspirar muito pouca simpatia, pois nenhum outro animal - exceto as formigas - foi tantas vezes mencionado como praga para a agricultura. Além disso, alguns psitácidas mostravam-se tão loquazes que inspiravam a séria desconfiança de serem animais demoníacos ou possessos, pois só três classes de entidades - anjos, homens e demônios - possuíam o dom da palavra. Nos dias de hoje, vários representantes dos Psittacidae ainda constituem uma ameaça para a agricultura, enquanto os indivíduos muito faladores continuam despertando a suspeita de estarem possuídos pelo demônio. Transcendendo a mera curiosidade, essa crença exemplifica o quão intrincadas podem ser as relações do homem com o chamado “mundo natural”, revelando um universo mais amplo e multifacetado do que se poderia supor a princípio. Nesse sentido, a existência de aves capazes de falar torna essa relação ainda mais complexa e evidencia que as dificuldades de estabelecer o limite entre o animal e o humano se estendem além dos primatas e envolvem as mais inusitadas espécies zoológicas.Since ancient times, parrots and their allies (Psittacidae) have fascinated Europeans by their striking colors and notable ability to interact with human beings. The discovery of the New World added new species to the international exotic animal trade, which for many centuries had brought beasts to Europe from Africa and the Orient. Lacking large mammals, tropical America participated in this trade with its most appealing species, essentially felines, primates and birds - especially parrots - which were shipped in large numbers. It should be noted, however, that at times these birds were not well liked. In fact, according to documents from colonial Brazil, only the ants rank higher than parrots as the animals most often mentioned as agricultural pests. On the other hand, some of these birds were so chatty that people suspected them to be demonic or possessed animals, since only three classes of beings - angels, men and demons - have the ability to speak. Nowadays, several Psittacidae still constitute a threat to agriculture, and the suspicion that extremely talkative birds were demon possessed has also survived. More than a joke or a mere curiosity, this belief exemplifies how intricate man’s relationships with the “natural world” may be. In this sense, the existence of birds that are able to speak adds a further twist to these relationships, demonstrating that the problem of establishing a boundary between the animal and the human does not only involve primates, but also includes some unusual zoological species

To hop or not to hop? the answer is in the bird trees

Birds can use different types of gaits to move on the ground: they either walk, hop, or run. Although velocity can easily explain a preference for running, it remains unclear what drives a bird species to favour hopping over walking. As many hopping birds are relatively small and arboreal, we wanted to test the link between size, arboreality and hopping ability. First, we carried out ancestral character state reconstructions of size range, hopping ability and ecology on over 1000 species of birds. We found that both hopping ability and arboreality were derived and significantly correlated traits in avian evolution. Second, we tested the influence of hopping ability on the morphology of the lower appendicular skeleton by quantifying the shape differences of the pelvis and the three long bones of the hind limbs in 47 avian species with different habitats and gait preferences. We used geometric morphometrics on 3D landmarks, digitized on micro-CT and surface scans of the pelvis, femur, tibiotarsus, and tarsometatarsus. Locomotion habits significantly influence the conformation of the pelvis, especially at the origin of hip and knee muscle extensors. Interestingly, ecology, more than locomotion habits, significantly changed tarsometatarsus conformation. The morphology of the distal part of the tarsometatarsus constrains digit orientation, which leads to a greater ability to perch, an advantageous trait in arboreality. The results of this work suggest an arboreal origin of hopping and illuminate the evolution of avian terrestrial locomotion

Osteology of the Shoulder Girdle in the Piciformes, Passeriformes and Related Groups of Birds

Abstract. A comparative study of the bones of the shoulder girdle in the Piciformes, Passeriformes and Coraciiformes, and also in related orders of birds such as the Trogoniformes, Coliiformes, Apodiformes, Strigiformes and Caprimulgiformes, is presented and discussed. A number of observed characters justify inclusion only the families Indicatoridae, Picidae, Capitonidae and Ramphastidae in the order Piciformes, while also demonstrating a close resemblance with the Passeriformes that suggests a monophyletic origin for these two orders. On the other hand, although the closely related Bucconidae and Galbulidae are not included in the Piciformes they more closely resemble the Coraciiformes, particularly the Meropidae, Coraciidae and Brachypteraciidae. Among the Coraciiformes, it was observed that the Upupidae closely resemble the Phoeniculidae and, to a lesser extent, the Bucerotidae (particularly Tockus). For other coraciiforms, observation of shoulder girdle osteology alone did not provide sufficient evidence to justify a family grouping or a clearer definition of the boundaries of this order