Showing posts with label frogs. Show all posts
Showing posts with label frogs. Show all posts

Friday, November 27, 2015

Amphibians and Squamates From Maastrichtian Cretaceous Iberia

Late Cretaceous (Maastrichtian) amphibians and squamates from northeastern Iberia

Authors:

Blanco et al

Abstract:

Maastrichtian biodiversity of medium- and large-sized terrestrial vertebrates is well known in Europe and, specifically, in the Iberian Peninsula. Regarding small-sized herpetofaunas (lissamphibians and squamates), only a few European sites have yielded a significant amount of fossils, and they are still poorly known from the Iberian Peninsula. Recent fieldwork carried out at several sites exposing the Tremp Formation (Southern Pyrenees) has revealed four new localities yielding microvertebrates. Two of them (L'Espinau and Serrat del Rostiar-1) are relatively diverse in herpetofauna, containing albanerpetontids, four different anurans (two different alytids, a pelobatid or gobiatid and a palaeobatrachid), as well as six types of squamates (including scincomorphs, iguanids, anguids and probably gekkotans). Most of these groups are shared with other Campanian-Maastrichtian localities from eastern Iberia although, in some cases, morphological differences might suggest the presence of new lower-level taxa (i.e., genera or species). Also remarkable is the presence of alytines and likely gekkotans that would represent the oldest records of these taxa in Europe and in the Iberian Peninsula, respectively. Taxa of Laurasian origin are common at the Serrat del Rostiar-1 and L'Espinau localities, while Gondwanan taxa are lacking in all cases. Evidence for Asian immigrants (i.e., alytines) is found amongst anurans. Some differences regarding the faunal composition could be explained by environmental factors (i.e., coastal wetlands vs. fluvial settings), although the possibility of taphonomic biases cannot be ruled out.

Thursday, January 01, 2015

First Frog Found Which Live Births Tadpoles


University of California, Berkeley, herpetologist Jim McGuire was slogging through the rain forests of Indonesia's Sulawesi Island one night this past summer when he grabbed what he thought was a male frog and found himself juggling not only a frog but also dozens of slippery, newborn tadpoles.

He had found what he was looking for: direct proof that the female of a new species of frog does what no other frog does. It gives birth to live tadpoles instead of laying eggs.

A member of the Asian group of fanged frogs, the new species was discovered a few decades ago by Indonesian researcher Djoko Iskandar, McGuire's colleague, and was thought to give direct birth to tadpoles, though the frog's mating and an actual birth had never been observed before.

"Almost all frogs in the world - more than 6,000 species - have external fertilization, where the male grips the female in amplexus and releases sperm as the eggs are released by the female," McGuire said. "But there are lots of weird modifications to this standard mode of mating. This new frog is one of only 10 or 12 species that has evolved internal fertilization, and of those, it is the only one that gives birth to tadpoles as opposed to froglets or laying fertilized eggs."

Monday, February 03, 2014

Maastrichtian Cretaceous Daemon-Frog Beelzebufo: Now Smaller, Armoured


New Material of Beelzebufo, a Hyperossified Frog (Amphibia: Anura) from the Late Cretaceous of Madagascar

Authors:

Evans et al

Abstract:

The extant anuran fauna of Madagascar is exceptionally rich and almost completely endemic. In recent years, many new species have been described and understanding of the history and relationships of this fauna has been greatly advanced by molecular studies, but very little is known of the fossil history of frogs on the island. Beelzebufo ampinga, the first named pre-Holocene frog from Madagascar, was described in 2008 on the basis of numerous disarticulated cranial and postcranial elements from the Upper Cretaceous (Maastrichtian) Maevarano Formation of Madagascar. These specimens documented the presence of a hyperossified taxon that differed strikingly from extant Malagasy frogs in its large size and heavy coarse cranial exostosis. Here we describe and analyse new, articulated, and more complete material of the skull, vertebral column, and hind limb, as well as additional isolated elements discovered since 2008. μCT scans allow a detailed understanding of both internal and external morphology and permit a more accurate reconstruction. The new material shows Beelzebufo to have been even more bizarre than originally interpreted, with large posterolateral skull flanges and sculptured vertebral spine tables. The apparent absence of a tympanic membrane, the strong cranial exostosis, and vertebral morphology suggest it may have burrowed during seasonally arid conditions, which have been interpreted for the Maevarano Formation from independent sedimentological and taphonomic evidence. New phylogenetic analyses, incorporating both morphological and molecular data, continue to place Beelzebufo with hyloid rather than ranoid frogs. Within Hyloidea, Beelzebufo still groups with the South American Ceratophryidae thus continuing to pose difficulties with both biogeographic interpretations and prior molecular divergence dates.

Wednesday, September 11, 2013

The Launching of FROGEE


A legit pic from here

Baumgartner better watch out!  The webbed ones want his record!

Tuesday, June 04, 2013

Hula Painted Frog is Not Extinct...and Not Related to What We Thought


The first amphibian to have been officially declared extinct by the International Union for Conservation of Nature (IUCN) has been rediscovered in the north of Israel after some 60 years and turns out to be a unique "living fossil," without close relatives among other living frogs.

The Hula painted frog was catalogued within the Discoglossus group when it was first discovered in the Hula Valley of Israel in the early 1940s. The frog was thought to have disappeared following the drying up of the Hula Lake at the end of the 1950s, and was declared extinct by the IUCN in 1996. As a result, the opportunity to discover more about this species' history, biology and ecology was thought to have disappeared.

However, a team of Israeli, German and French researchers now report in the scientific journal Nature Communications on an in-depth scientific analysis of this enigmatic amphibian.

Based on new genetic analyses of rediscovered individuals and the morphologic analyses of extant and fossil bones, the conclusion is that the Hula frog differs strongly from its other living relatives, the painted frogs from northern and western Africa. Instead, the Hula frog is related to a genus of fossil frogs, Latonia, which were found over much of Europe dating back to prehistoric periods and has been considered extinct for about a million years,

The results imply that the Hula painted frog is not merely another rare species of frog, but is actually the sole representative of an ancient clade of frogs (a group with a single common ancestor)

Tuesday, February 12, 2013

The Oligocene Indo-Asian Faunal Interchange

Diversification of rhacophorid frogs provides evidence for accelerated faunal exchange between India and Eurasia during the Oligocene

Authors:

1. Jia-Tang Li (a,b)
2. Yang Li (a,c)
3. Sebastian Klaus (d)
4. Ding-Qi Rao (a)
5. David M. Hillis (e)
6. Ya-Ping Zhang (a,f)

Affiliations:

a. State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China

b. Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China

c. College of Life Sciences, Sichuan University, Chengdu 610064, China

d. Department of Ecology and Evolution, Goethe University, 60438 Frankfurt am Main, Germany

e. Section of Integrative Biology and Center for Computational Biology and Bioinformatics, University of Texas at Austin, Austin, TX 78712

f. Laboratory for Conservation and Utilization of Bioresources, Yunnan University, Kunming 650091, China

Abstract:

The accretion of the Indian subcontinent to Eurasia triggered a massive faunal and floral exchange, with Gondwanan taxa entering into Asia and vice versa. The traditional view on the Indian–Asian collision assumes contact of the continental plates during the Early Eocene. Many biogeographic studies rely on this assumption. However, the exact mode and timing of this geological event is still under debate. Here we address, based on an extensive phylogenetic analysis of rhacophorid tree frogs, if there was already a Paleogene biogeographic link between Southeast Asia and India; in which direction faunal exchange occurred between India and Eurasia within the Rhacophoridae; and if the timing of the faunal exchange correlates with one of the recently suggested geological models. Rhacophorid tree frogs showed an early dispersal from India to Asia between 46 and 57 Ma, as reconstructed from the fossil record. During the Middle Eocene, however, faunal exchange ceased, followed by increase of rhacophorid dispersal events between Asia and the Indian subcontinent during the Oligocene that continued until the Middle Miocene. This corroborates recent geological models that argue for a much later final collision between the continental plates. We predict that the Oligocene faunal exchange between the Indian subcontinent and Asia, as shown here for rhacophorid frogs, also applies for other nonvolant organisms with an Indian–Asian distribution, and suggest that previous studies that deal with this faunal interchange should be carefully reinvestigated.

Wednesday, June 16, 2010

Tuesday, March 10, 2009

Amazonian Amphibian Diversity Traced to Andes

Colorful poison frogs in the Amazon owe their great diversity to ancestors that leapt into the region from the Andes Mountains several times during the last 10 million years, a new study from The University of Texas at Austin suggests.

This is the first study to show that the Andes have been a major source of diversity for the Amazon basin, one of the largest reservoirs of biological diversity on Earth. The finding runs counter to the idea that Amazonian diversity is the result of evolution only within the tropical forest itself.

"Basically, the Amazon basin is a 'melting pot' for South American frogs," says graduate student Juan Santos, lead author of the study. "Poison frogs there have come from multiple places of origin, notably the Andes Mountains, over many millions of years. We have shown that you cannot understand Amazonian biodiversity by looking only in the basin. Adjacent regions have played a major role."

Santos and Dr. David Cannatella, professor of integrative biology, published their findings this month in the journal PLoS Biology.


The tale of how the tropics became so diverse is a rather complicated one indeed.