Tag: reptile

The scaled king and his knight: 2 new giant bent-toed gecko species from New Guinea

The extremely complex geological history of New Guinea has allowed many of its animals and plants the chance to grow different enough to make a name for themselves. In the case of two newly described and unusually large gecko species – only a noble name would do. The two new species whose names respectively mean ‘knight’ and ‘king’ were discovered by a team led by Dr. Paul Oliver, The Australian National University and University of Melbourne, are described in the open-access journal ZooKeys.

Both new species belong to the world’s most diverse gecko genus Cyrtodactylus which comprises more than 200 species known to date. These reptiles are commonly called bent-toed or bow-fingered geckos due to their distinctive slender curved toes. They occur through Asia and Australia.

These 200 species vary greatly in size, build and colouration. However, one of the newly described species, called C. rex, meaning “king” in Latin, is the largest species in the genus, and among the biggest of all geckos in the world.

In general, the bent-toed geckos measure no more than 13 cm in length, yet the “gecko king” can grow up to 17 cm, with the females slightly bigger than the males. It is also characterised with upper body side covered in alternating regions of dark grey brown and medium brown. There are also variable in size and shape, but clearly defined dark grey-brown markings. All examined specimens are reported to have either four or five dark brown blotches or bands running down their original tails.

The second new species also bears a noble name – Cyrtodactyulus equestris, meaning ‘knight’ in Latin. It is also considered a giant among its relatives with its length of up to 14 cm for the females. Similarly to its larger relative, its head is large and wide, clearly distinct from the neck. Its upper side is coloured with alternating regions of light and medium brown. While in smaller individuals the patches are visibly defined by dark brown edging, such is missing in the larger ones, giving their pattern slightly faded appearance.

As a whole, the distribution of the two new geckos overlap, although the “gecko knight” is reported to prefer the relatively undisturbed hill or lower montane forests of northern New Guinea and its neighbour “the king” seems to stick to the surrounding lowlands.

While the larger size of the New Guinean bent-toed geckos seems to be an evolutionary trend, the role of potential factors such as competition, ecological diversification, isolation and dispersal remains quite a mystery.

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Original source:

Oliver PM, Richards SJ, Mumpuni, Rösler H (2016) The Knight and the King: two new species of giant bent-toed gecko (Cyrtodactylus, Gekkonidae, Squamata) from northern New Guinea, with comments on endemism in the North Papuan Mountains. ZooKeys 562: 105-130. doi: 10.3897/zookeys.562.6052

Single no more: First females of a Madagascan chameleon described with modern technologies

The first females of a scarcely known chameleon species from Northeast Madagascar have been described. Because of lack of genetic data, X-ray micro-computed tomography scans of the chameleon’s head were used for species assignment. Regrettably, the habitats of this and many other chameleon species are highly threatened by the ongoing deforestation in Madagascar. The study is published in the open-access journal Zoosystematics and Evolution.

Chameleons belong to the most popular animals of Madagascar and have been quite intensively studied in the past. However, many new species are still being discovered and described, and several species are only known by a single or a few specimens. Likewise, the chameleon species Calumma vatosoa from northeastern Madagascar was described in 2001 based on a single male. The identity of females of this species has been unclear until now.

Recently, the PhD student David Proetzel of the herpetology section of the Zoologische Staatssammlung Munchen (ZSM), Germany, found specimens of female chameleons in the collection of the Senckenberg Museum, Frankfurt am Main, Germany, that looked similar to Calumma vatosoa. The problem was, how to prove this? The specimens from Frankfurt were collected back in 1933 and therefore, the extraction of DNA for genetic analysis was not possible anymore.

Researchers of the ZSM have been using X-ray micro-computed tomography scans for a few years to study the internal morphology of organisms in a non-invasive way.

“With the help of Micro-CT you can investigate even the skeleton of very valuable samples like holotypes without destroying them,” explains David Proetzel.

“In chameleons the morphology of the skeleton, especially the skull, contains important characteristics that distinguish different species,” explains the researcher. “Here, the comparison of the skulls of the male and the female showed that they belong to the same chameleon species. With the help of modern technology we could describe females of Calumma vatosoa for the first time, and add another distribution locality of this species.”

“The habitats of many chameleon species, and not only, are highly threatened by the ongoing deforestation in Madagascar and we need rapidly to expand our knowledge about the biodiversity, so that suitable conservation measures can be taken,” he stresses.

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Original source:

Proetzel D, Ruthensteiner B, Glaw F (2016) No longer single! Description of female Calumma vatosoa (Squamata, Chamaeleonidae) including a review of the species and its systematic position. Zoosystematics and Evolution, 92 (1): 13-21. doi: 10.3897/zse.92.6464

The lizard of consistency: New iguana species which sticks to its colors found in Chile

During a field trip at 3000 metres above sea level, a group of scientists, led by Jaime Troncoso-Palacios, Universidad de Chile, discovered a new endemic iguana species, in the mountains of central Chile, scientists. Noticeably different in size and scalation, compared to the rest of the local lizards, what initially grabbed the biologists’ attention was its colouration. Not only was it unlike the already described ones, but also appeared surprisingly consistent within the collected individuals, even regardless of their sex. Eventually, it was this peculiar uniformity that determined the lizard’s name L. uniformis. The study is published in the open-access journal ZooKeys.

The researchers found the lizards quite abundant in the area, which facilitated their observations and estimations. Apart from a thorough description of the new iguana along with its comparisons to its related species, the present paper also provides an in-depth discussion about the placement of the new taxon, which had been confused with other species in the past.

While most of the other lizards from the area and its surroundings often vary greatly in colouration and pattern between populations and sexes, such thing is not present in the new species. Both males and females from the observed collection have their bodies’ upper side in brown, varying from dark on the head, through coppery on the back and light brown on the tail. The down side of the body is mainly yellowish, while the belly – whitish. The only variables the scientists have noticed in their specimens are slight differences in the shade with two females demonstrating unusual olive hues on their snouts. These differences in morphology were also strongly supported by the molecular phylogeny through the analysis of mitochondrial DNA, which was performed by Dr. Alvaro A. Elorza, from Universidad Andres Bello.

Accustomed to life in highland rocky habitats with scarce greenery, these lizards spend their active hours, estimated to take place between 09:00 h and 18:00 h hidden under stones. However, they might not be too hard to find due to their size of about 8.5 cm for the males and their abundance in the studied area. The females are more slender and measure 7 cm in length on average.

Having caught one of their specimens while holding a yellow flower in its mouth, the scientists conducted further examination of the stomach contents of the studied individuals and concluded that the species is omnivorous, feeding mainly on plants as well as insects and roundworms.

In conclusion, the researchers showed that there is still a huge gap in the knowledge of the close relatives of the newly described species and their “challenging taxonomy”.

 

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Original source:

Troncoso-Palacios J, Elorza AA, Puas GI, Alfaro-Pardo E (2016) A new species of Liolaemusrelated to L. nigroviridis from the Andean highlands of Central Chile (Iguania, Liolaemidae).ZooKeys 555: 91-114. doi: 10.3897/zookeys.555.6011

Three new fishing snake species fished out of the Andean slopes in South America

Commonly known as fishing snakes, the Synophis genus has been expanded with as many as three new species following a research in the Andean cloud forests of Amazonian Ecuador and Peru. Not only is the discovery remarkable due to the rarity of new snake species being discovered, but also because this is the first time this mysterious and already eight-member genus is recorded from Peru. The study is published in the open-access journal ZooKeys.

The three new species have been identified as a result of both field and laboratory work, undertaken by Dr. Omar Torres-Carvajal, Museo de Zoología QCAZ, Ecuador, in collaboration with herpetologists from Peru (CORBIDI) and the United States (Francis Marion University). The new species differ from their closest relatives in scale features, male sexual organs and DNA. The unusual discoveries took place in areas within the 1,542,644 km2 of the Tropical Andes hotspot, western South America.

Although they are commonly known as fishing snakes, these reptiles most likely do not eat fish. Their diet and behavior are poorly known. So far, it has only been reported that one species feeds on lizards.

The fishing snakes have long been known to live in cloud forests on both sides of the Andes of Colombia and Ecuador. Yet, it seems they have waited all along to make an appearance. The new species described herein, along with a recent description of one species from southwestern Ecuador also published in Zookeys, has duplicated the number of species of fishing snakes from four to eight over the span of several months.

During their recent expeditions to several localities along the Andes of Ecuador and Peru the authors collected several individuals of fishing snakes, which they suspected to be previously unknown. After comparing their specimens with those deposited in a number of natural history museums, the authors’ suspicions only became stronger.

Consequently, the scientists examined the male snakes’ sexual organs (hemipenes) and DNA evidence. The results left no doubts that the specimens belonged to three undescribed fishing snake species.

“We started working with fishing snakes a year ago as new specimens were collected in poorly explored areas of the Amazonian slopes of the Andes in Ecuador and Peru,” explains lead author Dr. Omar Torres-Carvajal. “At that time only four species of fishing snakes had been described, and they were recognized in the literature as one of the most rare and secretive groups of snakes in South America.”

“In less than a year, we and other herpetologists doubled the number of known species of fishing snakes, showing that their diversity had been greatly underestimated,” he points out.

“This story is similar to the story of the woodlizards (Enyalioides), a group of dragon-like lizards with more than half of its species discovered in recent years in the tropical Andes,” the scientist reminisces.

“This tells us that this hotspot is more diverse than we thought, so it is very important that basic biodiversity research is properly funded,” Dr. Torres-Carvajal concludes. “Otherwise, we might never know what other scaly creatures are crawling around us.”

 

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Original source:

Torres-Carvajal O, Echevarría LY, Venegas PJ, Chávez G, Camper JD (2015) Description and phylogeny of three new species of Synophis (Colubridae, Dipsadinae) from the tropical Andes in Ecuador and Peru. ZooKeys 546: 153-179. doi: 10.3897/zookeys.546.6533.