Allometric relationships among body mass, MUZZLE-tail length, and tibia length during the growth of Wistar rats1

PURPOSE : To investigate allometric relationships among body mass (BM), muzzle-tail length (MTL), and tibia length (TL) in Wistar rats and establish their growth rate change parameters. METHODS : Eighteen male and 18 female Wistar rats were studied from the 3rd to the 21st week of age. BM, MTL, and TL were measured daily, and relative growth was compared using allometry. RESULTS : A positive correlation between BM and MTL (p<0.05) and BM and TL (p<0.05) was observed. Males and females showed comparable curves; however, females had turning points at a younger age. The allometric relationship between BM and MTL presented a regular increase until reaching a mass of 351 g (males) and 405 g (females). BM and TL showed an initial increase until 185 g (males) and 182 g (females), and then reached a plateau that finished at 412 g (males) and 334 g (females), to display another increase. CONCLUSIONS : The allometric relationship of body mass with animal length and tibia length was comparable for male and female rats, with female rats maturing earlier. Animal longitudinal growth occurred in a single stage. In contrast, tibia length depicted two stages of accelerated growth with an intermediate period of deceleration.

Bases ósseas e musculares dos cortes comerciais da cauda de jacaré-do-Pantanal (Caiman yacare Daudin 1802) / Bone and muscular bases of commercial cuts from the Yacare Caiman (Caiman yacare, Daudin 1802) tail

A exploração comercial de jacaré-do-Pantanal (Caiman yacare) constitui importante cadeia produtiva no Estado de Mato Grosso. As características nutricionais e representatividade na massa corporal de crocodilianos tornaram a região da cauda objeto de estudos morfofisiológicos, evolutivos e tecnológicos. Como inexiste a caracterização anatômica dos músculos e ossos que constituem os cortes comerciais dessa região, objetivou-se descrever os músculos e correspondentes bases ósseas da cauda. Na descrição óssea, foram utilizados um exemplar adulto e seis juvenis. Para caracterização muscular, 24 espécimes juvenis foram conservados em freezer e dissecados a fresco, em ambos os antímeros, para verificação de simetria de ocorrência, fixações musculares, relacões de sintopia, forma e arquitetura muscular. As vértebras caudais são procélicas, exceto a primeira da série, e possuem na superfície ventral do corpo áreas para articulação com os processos hemais, exceto a primeira e as quatro ou cinco últimas. Os cortes comerciais da região são o filé de cauda, composto pelos músculos semiespinhal caudal, longuíssimo caudal, ilioisquiocaudal, caudofemoral longo, transverso e profundo da cauda, enquanto o corte ponta de cauda é constituído pelos músculos longuíssimo caudal e ilioisquiocaudal, com as cinco ou seis últimas vértebras caudais.

The commercial exploitation of the Yacare Caiman (Caiman yacare) has become a relevant commodity in the state of Mato Grosso, Brazil. Crocodilian's tail muscles nutritional characteristics and representativeness in body mass became the object of morphophysiological technological and evolutionary studies. The aim of this research was to report, for the first time, the anatomical characterization of muscle and bone bases of Pantanal Caiman meat cuts obtained from the tail. To describe the bones, we used one adult and six juvenile specimens of Pantanal Caiman. In order to study the muscle, 24 juvenile individuals were slaughtered and skinned, preserved in a -20oC freezer and thawed at the time of use, without any fixation. After evisceration, the specimens were dissected on both sides to verify structural symmetry, muscle attachments, sintopy relations, shape and muscular architecture. Caudal vertebrae are procoelous, except for the first of the series, and have sites on the ventral surface of their body where the hemal processes articulate, with the exception of the first and the last four or five vertebrae. The commercial meat cuts of the tail are the tail sirloin, composed of semispinal caudal, longissimus caudal, ilioischiocaudal, long caudofemoral, transverse and deep of the tail muscles, and also the tail tip, consisting of the longissimus caudal and ilioischiocaudal muscles, based on the last five or six caudal vertebrae.

Recovering missing data: estimating position and size of caudal vertebrae in Staurikosaurus pricei Colbert, 1970

Missing data is a common problem in paleontology. It makes it difficult to reconstruct extinct taxa accurately and restrains the inclusion of some taxa on comparative and biomechanical studies. Particularly, estimating the position of vertebrae on incomplete series is often non-empirical and does not allow precise estimation of missing parts. In this work we present a method for calculating the position of preserved middle sequences of caudal vertebrae in the saurischian dinosaur Staurikosaurus pricei, based on the length and height of preserved anterior and posterior caudal vertebral centra. Regression equations were used to estimate these dimensions for middle vertebrae and, consequently, to assess the position of the preserved middle sequences. It also allowed estimating these dimensions for non-preserved vertebrae. Results indicate that the preserved caudal vertebrae of Staurikosaurus may correspond to positions 1-3, 5, 7, 14-19/15-20, 24-25/25-26, and 29-47, and that at least 25 vertebrae had transverse processes. Total length of the tail was estimated in 134 cm and total body length was 220-225 cm.

Dados lacunares são um problema comum na paleontologia. Eles dificultam a reconstrução acurada de táxons extintos e limitam a inclusão de alguns táxons em estudos comparativose biomecânicos. Particularmente, estimar a posição de vértebras em séries incompletas tem sido feito com base em métodos não empíricos que não permitem estimar corretamente as partes ausentes. Neste trabalho apresentamos uma metodologia que permite estimar a posição de sequências médias preservadas de vértebras caudais no dinossauro saurísquio Staurikosaurus pricei, com base no comprimento e altura dos centros das vértebras anteriores e posteriores preservadas. Equações de regressão foram usadas para estimar essas dimensões para as vértebras médias e, consequentemente, para posicionar as sequências médias preservadas e para estimar o tamanho das vértebras não preservadas. Os resultados indicam que as vértebras caudais preservadas de Staurikosaurus corresponderiam às posições 1-3, 5, 7, 14-19/15-20, 24-25/25-26 e 29-47, e que pelo menos 25 vértebras possuíam processos transversos. O comprimento total da cauda foi estimado em 134 cm e o comprimento total do corpo em 220-225 cm.

A pterodactyloid pterosaur from the Upper Cretaceous Lapurr sandstone, West Turkana, Kenya

An isolated pterosaurian caudal cervical (~ postcervical) vertebra was recovered from the Upper Cretaceous Lapurr sandstone ofWest Turkana, northwestern Kenya. The vertebral centrum is short, wide, and dorsoventrally compressed. Although the specimen is lightly built similar to most pterosaurs, it is here referred to Pterodactyloidea and tentatively to the Azhdarchidae in that it lacks pneumatic features on both the centrum and neural arch. This represents one of the few pterosaurs recovered from the entirety of Afro-Arabia, the first pterosaur recovered from the Cretaceous of East Africa, and, significantly, a specimen that was recovered from fluvial deposits rather than the near-shore marine setting typical of most pterosaur discoveries.

Uma vértebra cervical caudal isolada de pterossauro (~ pós-cervical) foi recuperada do Cretáceo Superior do arenito de Lapurr do Oeste de Turkana, noroeste do Quênia. O centro vertebral é curto, largo e comprimido dorsoventralmente. Embora o espécime seja leve como grande parte dos pterossauros, ele é aqui referido a Pterodactyloidea e tentativamente a Azhdarchidae no que diz respeito à ausência de características pneumáticas tanto no centro quanto no arco neural. Este representa um dos poucos pterossauros recuperados do conjunto Afro-Arábia, o primeiro pterossauro proveniente do Cretáceo do Leste da África e, significativamente, um espécime que foi recuperado de depósitos fluviais e não do cenário marinho próximo da costa típico da maioria das descobertas de pterossauros.