Search results for "amphibia"

Spatial Context of Breeding Ponds and Forest Management Affect the Distribution and Population Dynamics of the Great Crested Newt

2016

Intensive forest management and landscape degradation are threats to amphibian populations. We modelled and compared the extinction and colonization dynamics of the great crested newt in four different spatial contexts that describe landscape change from past to present and future forest landscapes in eastern Finland. In future landscape scenarios, we explored the effects of two forest use intensities with different logging rotation times. The introduction of fish into breeding ponds has been the main cause of local extinctions of the great crested newt. In the future, intensifying land-use and shorter logging rotation will decrease the connectivity between ponds the most. In conservation p…

Pentadactyl manus of the Metoposaurus krasiejowensis from the Late Triassic of Poland, the first record of pentadactyly among Temnospondyli

2020

Abstract Temnospondyli are commonly believed to have possessed four digits in the manus and five in the pes. However, actual finds of articulated autopodia are extremely rare. Therefore, an articulated, slightly incomplete forelimb skeleton with preserved manus of Metoposaurus krasiejowensis from the Late Triassic of Poland is important in providing new details about the structure and ossification sequence in the temnospondyl limb. The most important observation is the presence of five metacarpals in this specimen. This allows reconstructing the manus as pentadactyl. The number of phalanges and the distribution of distal articulation facets allow reconstruction of the digit formula as (2?)‐…

Amphibians and squamate reptiles from the stratigraphic unit Xb of El Salt (Middle Palaeolithic; Alcoy, Spain): palaeoenvironmental and palaeoclimati…

2020

The locality of El Salt (Middle Paleolithic, Alcoy, Spain) is mainly known by having one of the youngest Neanderthals records of the southeastern Iberian Peninsula. In this work, we have analysed the herpetofaunal fossils from the upper part of stratigraphic unit Xb, dated at 52.3 ± 4.6 ka (MIS 3). The faunal list is composed by three taxa of anurans (Alyte obstetricans, Bufo bufo s.l., and Epidalea calamita), one taxon of blanid (Blanus cinereus s.l.), two taxa of lizards (Chalcides bedriagai and cf. Acanthodactylus erythrurus), and one taxon of snakes (cf. Rhinechis scalaris). All of them have a broad distribution range in the Mediterranean, with wide ecological preferences range. This as…

Palaeohistology helps reveal taxonomic variability in exceptionally large temnospondyl humeri from the Upper Triassic of Krasiejów, SW Poland

2023

For more than twenty years, palaeontological excavations have been carried out at the Upper Triassic site of Krasiejów (south-west Poland), providing thousands of skeletal elements belonging to various tetrapod groups. However, almost all bones are preserved in a disarticulated state. This generates problems in taxonomic assignment among closely related groups, e.g., stereospondyl amphibians. As far as cranial elements, the pectoral girdle bones and the intercentra are very diagnostic, while all other remaining skeletal elements are difficult to unambiguously assign between either the capitosaurid Cyclotosaurus intermedius or the trematosaurid Metoposaurus krasiejowensis, both originating f…

Much more than a clasp : evolutionary patterns of amplexus diversity in anurans

2020

The evolution and diversification of animal reproductive modes have been pivotal questions in behavioural ecology. Amphibians present the highest diversity of reproductive modes among vertebrates, involving various behavioural, physiological and morphological traits. One such feature is the amplexus, which is the clasp or embrace of males on females during reproduction and is found almost universally in anurans. Hypotheses about the origin of amplexus are limited and have not been tested thoroughly, nor have they taken into account evolutionary relationships in most comparative studies. However, these considerations are crucial to an understanding of the evolution of reproductive modes. Her…

Breeding phenology of Bufo viridis Laurenti, 1768 in Sicily (S Italy)

2006

Inhibition of amphibian egg development by histones

1966

Uova di Anuri (Discoglossus pictus) sono state trattate con istoni. II trattamento con la frazione ricca in lisina (0,4-0,1 mg/ml) durante la segmentazione causa blocco alle prime divisioni. Con concentrazioni minori (0,05–0,025 mg/ml) lo sviluppo si arresta allo stadio di gastrula. La sensibilita al trattamento decresce notevolmente dopo la gastrulazione. La frazione ricca in arginina e risultata meno efficace.

Übertragung von Verhaltensweisen durch Transplantation von Anlagen neuroanatomischer Strukturen bei Amphibienlarven

2010

By replacing parts of the neural plate (prospective medulla oblongata) of Triturus vulgaris by neural ectoderm of Xenopus laevis larval chimaeras were obtained, which showed donorlike rhythmical movements of distinct parts of the visceral musculature according to the place of implantation. Especially the branchial region with its external gills showed rhythmical movements and is the special object of this investigation.

Amphibian Immune System

1998

The temnospondyl amphibian Cyclotosaurus from the Upper Triassic of Poland

2005

A gap in the Late Triassic fossil record of the capitosaur amphibian Cyclotosaurus is filled by new material from lacustrine deposits at Krasiejow, Poland, corresponding in age to the Lehrberg Beds (late Carnian) of Germany. The skull of the Polish cyclotosaur is intermediate in several respects between that of Cyclotosaurus robustus from the middle Carnian Schilfsandstein of Germany and the younger C. mordax from the early Norian Stubensandstein. It shows a decrease in the width of the skull and in the degree of con- cavity of the posterior margin of the skull roof. The differ- ences are significant enough to warrant erection of a novel species, the name Cyclotosaurus intermedius sp. nov. …