Implications of flexible-shelled eggs in a Cretaceous choristoderan reptile

Flexible, or soft-shelled, eggs are almost unknown in the fossil record, leaving large gaps in our knowledge of the reproductive biology of many tetrapod clades. Here, we report two flexible-shelled eggs of the hyphalosaurid choristodere Hyphalosaurus baitaigouensis from the Early Cretaceous of China, one containing an embryo and the second associated with a neonate. Choristoderes are an enigmatic group of aquatic reptiles that survived the K–T extinction but died out in the Miocene. Hyphalosaurids, a specialized clade of Choristodera, resemble miniature plesiosaurs and are considered to be primarily aquatic in habit. Scanning electron microscopy of samples from the eggs reveals a thin, non-columnar external mineralized layer characterized by rounded nodes and tentatively identified poorly structured irregular pores, with an underlying amorphous layer presumably representing decomposed protein fibrils. While the relationships of Choristodera remain controversial, eggshell microstructure more closely resembles that of Lepidosauromorpha (the lineage including lizards) as opposed to that of Archosauromorpha (the lineage including birds and crocodiles).     

Climate warming and the evolution of morphotypes in a reptile

Climate warming is known to have effects on population dynamics through variations in survival, fecundity and density. However, the impacts of climate change on population composition are still poorly documented. Morphotypes are powerful markers to track changes in population composition. In the common lizard, Lacerta vivipara , individuals display two types of dorsal patterns: reticulated (R individuals) and linear (L individuals). We examined how local warming affected intrapopulation frequencies of these morphotypes across 11 years. We observed changes in morph frequency of dorsal patterns across years, paralleling the rise of spring temperatures. The proportion of R individuals increased with June temperatures in juveniles, yearlings, and adult males and females. Three mechanisms could explain these changes: phenotypic plasticity, microevolution and/or dispersal between populations. We investigated the ontogenetic determinism, fitness and recruitment rates associated with dorsal morphotypes. Dorsal pattern ontogeny showed temperature dependence but this relationship was not associated with the warming trend during this study. We found variation by morphotype in survival and clutch size, but these factors did not explain R frequency increases. Among all the parameters considered in this study, only a decrease of immigration, which was more pronounced in the L morphotype, could explain the change in population composition. To our knowledge, this provides the first evidence of the impact of climate warming on population composition due to its effects on immigration.     

A new Early Permian reptile and its significance in early diapsid evolution

The initial stages of evolution of Diapsida (the large clade that includes not only snakes, lizards, crocodiles and birds, but also dinosaurs and numerous other extinct taxa) is clouded by an exceedingly poor Palaeozoic fossil record. Previous studies had indicated a 38 Myr gap between the first appearance of the oldest diapsid clade (Araeoscelidia), ca 304 million years ago (Ma), and that of its sister group in the Middle Permian (ca 266 Ma). Two new reptile skulls from the Richards Spur locality, Lower Permian of Oklahoma, represent a new diapsid reptile: Orovenator mayorum n. gen. et sp. A phylogenetic analysis identifies O. mayorum as the oldest and most basal member of the araeoscelidian sister group. As Richards Spur has recently been dated to 289 Ma, the new diapsid neatly spans the above gap by appearing 15 Myr after the origin of Diapsida. The presence of O. mayorum at Richards Spur, which records a diverse upland fauna, suggests that initial stages in the evolution of non-araeoscelidian diapsids may have been tied to upland environments. This hypothesis is consonant with the overall scant record for non-araeoscelidian diapsids during the Permian Period, when the well-known terrestrial vertebrate communities are preserved almost exclusively in lowland deltaic, flood plain and lacustrine sedimentary rocks.     

Subhabitat variability: A key to the high reptile diversity in chenopod shrublands

Abstract The herpetofauna of one hectare of chenopod shrubland near Roxby Downs in arid South Australia was studied from January 1991 until June 1993. The subhabitat preferences of 27 reptile species and one frog species were investigated by analysing capture rates, from more than 1800 captures in 401 pit traps. Although the site was characterized by relatively uniform cover of the dominant plant species Atriplex vesicaria, significant variation occurred in rock cover, and in edaphic and floristic features. Ctenophorus fordi, Ctenotus brooksi and Lerista labialis were strongly associated with sandy regions while Tympanocryptis intima, Diplodactylus tessellatus and Ctenotus strauchii were largely restricted to rocky subhabitats. Ctenotus leonhardii was strongly associated with a high density of Maireana species. Subhabitat preference of some of these species could be explained by the defence strategies they employed. Several species such as Ctenophorus nuchalis, Pogona vitticeps, Tympanocryptis lineata, Diplodactylus stenodactylus, Rhynchoedura ornata, Menetia greyii and Neobatrachus centralis were subhabitat generalists within the study site. The biological appropriateness of using a smaller number of subhabitat groupings, rather than the square root of the number of study sites, was confirmed in this study. Five subhabitat groups yielded meaningful preference data for more species than did 10 or 20 groups, and did not lose resolution achieved through higher level clustering.     

Bone-eating Osedax worms lived on Mesozoic marine reptile deadfalls

We report fossil traces of Osedax, a genus of siboglinid annelids that consume the skeletons of sunken vertebrates on the ocean floor, from early-Late Cretaceous (approx. 100 Myr) plesiosaur and sea turtle bones. Although plesiosaurs went extinct at the end-Cretaceous mass extinction (66 Myr), chelonioids survived the event and diversified, and thus provided sustenance for Osedax in the 20 Myr gap preceding the radiation of cetaceans, their main modern food source. This finding shows that marine reptile carcasses, before whales, played a key role in the evolution and dispersal of Osedax and confirms that its generalist ability of colonizing different vertebrate substrates, like fishes and marine birds, besides whale bones, is an ancestral trait. A Cretaceous age for unequivocal Osedax trace fossils also dates back to the Mesozoic the origin of the entire siboglinid family, which includes chemosynthetic tubeworms living at hydrothermal vents and seeps, contrary to phylogenetic estimations of a Late Mesozoic–Cenozoic origin (approx. 50–100 Myr).     

A comparison of the reproductive parameters of females of two reptile tick species

In comparisons of females of two reptile tick species Aponomma hydrosauri and Amblyomma limbatum, Ap. hydrosauri was initially larger, and after mating on the host engorged faster and remained attached for a shorter time before completing engorgement and detaching. Amb. limbatum had a longer period of engorgement, and achieved a greater engorged weight. Engorged Amb. limbatum females laid significantly more eggs than equivalent sized Ap. hydrosauri. Although the two species are ecologically similar and were collected from the same site for this study, their reproductive differences probably reflect adaptations to different conditions in their largely allopatric ranges.     

Morphology of the stomach of the tropical house gecko Hemidactylus mabouia (Squamata: Gekkonidae)

Rodrigues Sartori, S. S., Nogueira, K. O. P. C., Rocha, A. S. and Neves, C. A. 2011. Morphology of the stomach of the tropical house gecko Hemidactylus mabouia (Squamata: Gekkonidae). —Acta Zoologica (Stockholm) 92 : 179–186. Hemidactylus mabouia is a common species in Brazil, which facilitates its use in research in several areas and allows display it as a benchmark for studies with reptiles. To study the morphology of the stomach of H. mabouia, we carried out anatomical, histological and histochemical analysis. The stomach of H. mabouia is ‘J’ shaped and can be divided into oral fundic (OF), aboral fundic (AF) and pyloric regions. The surface epithelium is composed of mucosecretory cells (MC) containing neutral mucins. In the lamina propria of the OF region, are large ramified tubulo‐acinar glands, which become smaller, less ramified and more tubular towards the AF region, and are simple tubular and short in the pyloric region. The fundic glands contain differentiated neck and pit. The neck is composed of MC containing neutral mucins and the pit is made of oxyntopeptic cells (OC). The OC of the OF region contained many zymogen granules, while those of the AF region contained few zymogen granules and many mitochondria, which suggests the existence of a gradient of pepsinogen and hydrochloric acid secretion. Pyloric glands consisted of MC containing neutral mucins and both argyrophil and argentaffin endocrine cells.     

Visitor behavior in zoos: A review

Abstract

Visitors are integral components of zoological parks and their importance has led to a research area devoted to understanding the people–zoo relationship. This paper reviews, and provides a point of entry into, the literature relating to visitor research in zoos. The field emerged relatively recently and is diverse and interdisciplinary (it shares common ground with sociology, education, psychology, zoology, and other academic disciplines). Several areas can be identified in the literature (audience analysis, circulation and orientation, exhibit evaluation, and interactions with animals), and these areas have revealed visitors' demographic and behavioral characteristics, people's behavioral responses to endogenous and exogenous factors, the impact of exhibit design, and visitors' movements around zoos. Limitations of existing work include independence between research areas, lack of international studies, limited generalizability of results, and the minority status of the field. Therefore, suggestions for future work include integrating different research areas, more research from outside Europe and America, and increased interaction within the visitor research community.     

Geographic variation in the age of temperate-zone reptile and amphibian species: Southern Hemisphere species are older

Despite controversy over alternative definitions, the species is the fundamental operational unit of biodiversity, and species are the building-blocks of conservation. But is a ‘species’ from one part of the world the same as a ‘species’ from elsewhere? Our meta-analysis of molecular phylogenetic data reveals that reptile and amphibian species distributed in temperate-zone areas of the Northern Hemisphere are younger than taxa from the Southern Hemisphere, probably reflecting the greater impact of past climatic variation on Northern Hemisphere habitats. Because a species'' age may influence its vulnerability to anthropogenic threats, geographical variation in species ages should be incorporated into conservation planning.     

Pyrosequencing of prey DNA in reptile faeces: analysis of earthworm consumption by slow worms

Little quantitative ecological information exists on the diets of most invertebrate feeding reptiles, particularly nocturnal or elusive species that are difficult to observe. In the UK and elsewhere, reptiles are legally required to be relocated before land development can proceed, but without knowledge of their dietary requirements, the suitability of receptor sites cannot be known. Here, we tested the ability of non-invasive DNA-based molecular diagnostics (454 pyrosequencing) to analyse reptile diets, with the specific aims of determining which earthworm species are exploited by slow worms (the legless lizard Anguis fragilis) and whether they feed on the deeper-living earthworm species that only come to the surface at night. Slow worm faecal samples from four different habitats were analysed using earthworm-specific PCR primers. We found that 86% of slow worms (N=80) had eaten earthworms. In lowland heath and marshy/acid grassland, Lumbricus rubellus, a surface-dwelling epigeic species, dominated slow worm diet. In two other habitats, riverside pasture and calciferous coarse grassland, diet was dominated by deeper-living anecic and endogeic species. We conclude that all species of earthworm are exploited by these reptiles and lack of specialization allows slow worms to thrive in a wide variety of habitats. Pyrosequencing of prey DNA in faeces showed promise as a practical, rapid and relatively inexpensive means of obtaining detailed and valuable ecological information on the diets of reptiles.     

PERMANENT GENETIC RESOURCES: Development of microsatellite markers and analysis of their inheritance in the Australian reptile tick, Bothriocroton hydrosauri

Despite long-term study, the mechanism explaining the parapatric distribution of two Australian reptile tick species is not understood. We describe the development of primers amplifying 10 microsatellite Bothriocroton hydrosauri loci, for the study of population structure and dispersal patterns of this tick. The numbers of alleles per locus ranged from two to seven in ticks from the study site, and the observed heterozygosity between 0.28 and 0.69. Pedigree analysis indicates that one locus is inherited in a non-Mendelian manner in three families, which was not explained by null allele presence.     

广西猫儿山国家级自然保护区的两栖爬行动物

2004年5月～2005年12月,对猫儿山国家级自然保护区的两栖爬行动物进行了初步调查,新观察和采集到两栖动物10种、爬行动物17种.至此,猫儿山共有两栖动物35种、爬行动物38种.     

The cranial anatomy and relationships of Secodontosaurus, an unusual mammal-like reptile (Synapsida: Sphenacodontidae) from the early Permian of Texas

The cranial anatomy of the Early Permian sphenacodontid synapsid Secodontosaurus is redescribed. There is no evidence for recognition of more than one species of Secodontosaurus, and S. willistoni is declared a junior subjective synonym of S. obtusidens. Numerous derived characters (autapomorphies), mainly related to the unusually slender and slightly elongated skull, distinguish Secodontosaurus. The cranial specializations are interpreted as an adaptation toward a feeding strategy which involved preying upon small tetrapods that attempted to avoid capture by hiding in crevices and burrows. A cladistic analysis supports the following hypotheses of relationships: (a) the Sphenacodontidae is the nearest sister taxon of Therapsida; (b) Secodontosaurus, Sphenacodon, Ctenospondylus and Dimetrodon share a more recent common ancestor with one another than any of them do with Haptodus, and (c) Secodontosaurus shares a more recent common ancestor with Dimetrodon than with either Sphenacodon or Ctenospondylus. The latter hypothesis suggests that the sphenacodont subfamily 'Sphenacodontinae' is paraphyletic and, therefore, invalid.     

动物园展馆评估系统的建立及应用

在全面阐述动物园展馆评估方法的基础上,建立了从游客、动物和员工三个角度评估展馆的新的指标体系,并在搬迁前哈尔滨动物园的象馆、猩猩馆和水禽馆应用了该方法。评估结果显示：象馆的综合评估总分为84．1分,水禽馆为83．5分,猩猩馆为58．8分。象馆和水禽馆的总体使用效果稍好,而猩猩馆在平面布局、通风、采光和排水设施等方面存在问题,未能很好地吸引游客、保障动物健康和方便员工操作。最后针对评估结果提出了新展馆设计的几点建议。     

Male attractiveness covaries with fighting ability but not with prior fight outcome in house crickets

In many species males that tend to win fights against othermales are more attractive to females. There are three ways inwhich male fighting ability and attractiveness may be associated:(1) attractiveness and fighting ability are influenced by thesame underlying traits (e.g., body size), (2) females prefermales that have directly observed winning fights, or (3) winningprevious fights indirectly improves a male's chance of beingpreferred by females. The last possibility may arise as a consequenceof the "loser effect"; in many species when a male loses a fighthis probability of losing subsequent fights increases. Thereare, however, no studies testing whether such a "loser effect"also influences male attractiveness. Here we show that maleattractiveness and fighting ability are positively correlatedin the house cricket, Acheta domesticus. Our experiment wasdesigned so that females could not directly observe the outcomeof fights, thus eliminating possibility (2) above. We then testedbetween possibilities (1) and (3) by making use of the factthat in some cricket species the "loser effect" can be eliminatedexperimentally by ‘shaking’ a male and stimulatingthe motor program for flying. We showed that in A. domesticus‘shaking’ does affect the outcome of subsequentfights. Males that had won two previous fights were less likelyto win a fight after being ‘shaken’ than when subjectto a control treatment. In contrast, males that had lost twoprevious fights were more likely to win a fight after being‘shaken’ than when they were not shaken. There was,however, no effect of ‘shaking’ on male attractiveness.We conclude that the "loser effect" does not alter the tendencyfor large, dominant males to be attractive to females. Instead,it appears that there are traits correlated with both fightingability and attractiveness. One such trait is body size. Fightwinners were significantly larger than losers and attractivenesswas positively correlated with male body size.     

广东鼎湖山国家级自然保护区爬行动物多样性与保护

2006～2011年采用野外调查和访问调查相结合的方法,对广东鼎湖山国家级自然保护区爬行动物进行了专项调查研究。迄今,该保护区已记录爬行动物2目12科54种,其中6种为本次调查发现的新纪录,分别是截趾虎Gehyra mutilata、丽棘蜥Acanthosaura lepidogaster、棕黑腹链蛇Amphiesma sauteri、黑领剑蛇Sibynophis collaris、细白环蛇Lycodon subcinctus和乌龟Mauremys reevesii。本次调查野外发现爬行动物共38种,其中包括珍稀濒危物种平胸龟Platysternon megacephalum,16种文献有记载的爬行动物在本次调查中未发现。访问调查发现6只四眼斑水龟Sacalia quadriocellata,很可能来自鼎湖山。基于调查结果,对该保护区爬行动物多样性及受胁因素进行了探讨,并提出了4点保护管理建议。     

Visitor monitoring methods for managing public use pressures in the Danube Floodplains National Park, Austria

National parks in close proximity to large urban areas, such as the Danube Floodplains National Park near Vienna, need an intensive monitoring of recreational use due to the high number of visitors and the highly fragmented natural settings. Visitors in the National Park were monitored using an approach that integrated long-term video monitoring, counts by human observers, specific visitor interviews and route analysis by the application of GIS tools. The combination of monitoring and survey data allows a thorough analysis of public use patterns, as illustrated by a case study of dog walkers in the park. Results demonstrate the value of integrated monitoring approaches, and serve as a basis for improved sustainable management of the Danube Floodplains National Park.     

Remembering Exhibitions on Race in the 20th-century United States

ABSTRACT   This museum review places the American Anthropological Association's recent exhibition entitled "Race: Are We So Different?" into historical context by comparing it to other major exhibitions on race in the 20th century. I argue that although exhibitions on race in the 19th-century United States are frequently examined in the historical and anthropological literature, later exhibitions from the 20th century are frequently forgotten. In particular, I compare the AAA's recent exhibition to displays originally crafted for the 1915 and 1933 World's Fairs.