A Phenotypic Point of View of the Adaptive Radiation of Crested Newts (Triturus cristatus Superspecies, Caudata, Amphibia)

A synoptic review of the Amphibians of Iran: bibliography, taxonomy, synonymy, distribution, conservation status, and identification key to the eggs, larvae, and adults

This study provides an illustrated account, a comprehensive update of the systematics, and a bibliography of the 15 species of anurans in five families, eight genera; and of the six species of urodeles in two families, four genera in Iran. Bufonidae, with eight species, is the most diverse family; Salamandridae has five species and Ranidae has four species. This study also presents updated identification keys for the eggs, larvae, and metamorphosed amphibians of Iran. We designated specimen NMW 19855.1 as neotype of Pelophylax persicus (Schneider, 1799) comb. nov.. Along with distribution maps obtained from all the reliable localities and museum specimens known at this time, the modelled habitat of species, and for the first time, the National Red List of amphibians based on the IUCN red list categories and criteria. Based on our evaluation we propose to categorize Bufo eichwaldi, Paradactylodon persicus, Neurergus derjugini, and N. kaiseri as Vulnerable at National Red List, and to move Bufotes (Calliopersa) luristanicus, B. (C.) surdus, Firouzophrynus olivaceus, and Rana pseudodalmatina from the category of Least Concern (LC) to Near Threatened (NT). The National Red List of amphibians that we propose has significant implications for endangered species management and conservation. Forty-one percent of amphibian species in Iran are endemic to the country, and more than forty percent of the Iranian amphibians are at risk of extinction. Zagros Mountain forest and Hyrcaniain forests have more than 80% (i.e. 18 species) of the diversity of Iranian amphibians. A considerable amount of scientific literature published on Iranian amphibians in Persian language is not easily accessible to researchers outside Iran. This monograph attempts to remedy the situation and provides broader access to international herpetology. We recognize that taxonomy is always in a state of flux, and the names and synonymies used here reflect our current view.

Patterns of correlations and locomotor specialization in anuran limbs: association with phylogeny and ecology

As anuran saltatory locomotion has specific functional requirements achieved through certain intra- and inter-limb proportions, we analyzed pattern and degree of morphological integration in limbs of ten anuran species to reveal the relationship of shared developmental programs of serially homologous structures and locomotor specialization. Our main objectives were (1) to examine if morphological and functional differences in forelimb and hindlimb were associated with reduced covariation between limbs, (2) and to reveal patterns of correlation between species and the roles played by evolutionary history (phylogeny) and ecology (lifestyle and habitat use). Species with different locomotor behaviours (walking, jumping, hopping, running, climbing, swimming and burrowing) were used. Partial correlations showed that species shared similar patterns of functionally based morphological integration, with increased correlations in elements within limbs and reduced correlations between limbs. This was mainly based on strong correlations between proximal elements, humerus-radioulna and femur-tibiofibula. To test the influence of phylogenetic relationships and ecological demands we used different matrices (correlation similarity matrix, ecological similarity matrix, matrices of phylogenetic distance and morphological distance). The changes in correlation patterns are shown to be dissociated from phylogeny. On the other hand, they are to some extent shaped by habitat use and locomotion, as the species with similar locomotor behaviour also tend to have stronger similarity in integration patterns. The results from this study provide insight into the processes underlying the evolutionary change of anuran limbs, highlighting function as the main factor that shaped morphological integration of the examined species.

An Extremely Peramorphic Newt (Urodela: Salamandridae: Pleurodelini) from the Latest Oligocene of Germany, and a New Phylogenetic Analysis of Extant and Extinct Salamandrids

We describe an Oligocene newt specimen from western Germany that has gone practically unnoticed in the literature despite having been housed in the Museum für Naturkunde (Berlin) for a century. It is referable to the coeval Chelotriton, but is unusually peramorphic; for many characters it is more peramorphic than all other caudates or even all other lissamphibians. Most noticeable are the position of the jaw joints far caudal to the occiput, the honeycombed sculpture on the maxilla, and the possible presence of a septomaxilla (which would be unique among salamandrids). Referral to a species would require a revision of the genus, but the specimen likely does not belong to the type species. A phylogenetic analysis of nonmolecular characters of Salamandridae, far larger than all predecessors, confirms the referral to Chelotriton. It further loosely associates the Oligocene Archaeotriton and the Miocene Carpathotriton with the extant Lissotriton, though the former may alternatively lie outside Pleurodelinae altogether. The Miocene? I. randeckensis may not belong to the extant Ichthyosaura. The Miocene “Triturus” roehrsi is found neither with the extant Ommatotriton nor with Lissotriton, but inside an Asian/aquatic clade or, when geographic distribution is included as a character, as the sister-group to all other European molgins. The main cause for discrepancies between the results and the molecular consensus is not heterochrony, but adaptations to a life in mountain streams; this is the most likely reason why the Paleocene Koalliella from western Europe forms the sister-group to some or all of the most aquatic extant newts in different analyses. We would like to urge neontologists working on salamandrids to pay renewed attention to the skeleton, not limited to the skull, as a source of diagnostic and phylogenetically informative characters.

Extinction events can accelerate evolution

Extinction events impact the trajectory of biological evolution significantly. They are often viewed as upheavals to the evolutionary process. In contrast, this paper supports the hypothesis that although they are unpredictably destructive, extinction events may in the long term accelerate evolution by increasing evolvability. In particular, if extinction events extinguish indiscriminately many ways of life, indirectly they may select for the ability to expand rapidly through vacated niches. Lineages with such an ability are more likely to persist through multiple extinctions. Lending computational support for this hypothesis, this paper shows how increased evolvability will result from simulated extinction events in two computational models of evolved behavior. The conclusion is that although they are destructive in the short term, extinction events may make evolution more prolific in the long term.