Topic
Hypsilurus
About: Hypsilurus is a research topic. Over the lifetime, 5 publications have been published within this topic receiving 225 citations.
Papers
TL;DR: Field and laboratory studies of thermal availability and temperature selection reveal that Hypsilurus spinipes show little overt thermoregulatory behavior, and Quantitative analysis of perch-site characteristics revealed minor but significant habitat selection that may have elevated the lizards' body temperatures.
Abstract: Unlike all other Australian agamid lizards, forest dragons (Hypsilurus spp.) are restricted to cool moist forest habitats where there is little light penetration and, thus, little opportunity for heliothermy. In keeping with this habitat preference, our field and laboratory studies of thermal availability and temperature selection reveal that Hypsilurus spinipes show little overt thermoregulatory behavior. Body temperatures of five radio-tracked lizards were low and variable (11-26 C), highly correlated (r > 0.96) with operative temperatures measured at the same time, and lower in the field than in a laboratory thermal gradient, where the lizards consistently avoided temperatures < 16 C. Quantitative analysis of perch-site characteristics, compared to availability, revealed minor but significant habitat selection (for high, vertical perches, of intermediate diameters, in areas with relatively open canopy) that may have elevated the lizards' body temperatures. Although other Australian agamid lizards differ from H. spinipes in their heliothermic behavior and preference for open habitats, they share a correlated suite of traits (e.g., ambush predation, reliance on camouflage to evade predators) that centers on prolonged immobility. These features are retained by H. spinipes in its densely forested habitat, where the high "costs" of heliothermy have favored a shift to extreme thermoconformity.
34 citations
TL;DR: A new species of agamid lizard of the genus Hypsilurus from northern Papua New Guinea is described, characterized by its small adult size, scalational features, small nuchal and dorsal crests, and distinctive dorsal color pattern of brown and white chevrons.
Abstract: We describe a new species of agamid lizard of the genus Hypsilurus from northern Papua New Guinea. The new species is characterized by its small adult size, scalational features, small nuchal and dorsal crests, and distinctive dorsal color pattern of brown and white chevrons. It is a member of the H. godeffroyi species group, but otherwise, its closest relative is not obvious. The species is currently known from two of the outlying North Coast ranges, but following the pattern seen in several other species endemic to this region, it will likely prove to occur along much of the northern lowlands of New Guinea.
3 citations
TL;DR: Tree topology, inferred divergence dates, palaeogeographical and palaeoclimatic data are all consistent with Miocene immigration into Australia from the north by mesic forest ecomorphs, followed by initial diversification in mesic habitats before radiation into xeric habitats facilitated by increasing aridity.
Abstract: Recent mtDNA phylogenies of Australasian agamid lizards are highly incongruent with existing morphological views. To resolve this discrepancy we sequenced two nuclear gene regions, c-mos and brain-derived neurotrophic factor (BDNF). These were highly concordant with each other and the mtDNA phylogeny, but not the morphology. A combined molecular analysis reveals substantial hidden support (additional phylogenetic signal that emerges only when the data sets interact in a combined analysis). Bayesian posteriors, and a partitioned bootstrap procedure introduced here, indicate strong support for most nodes. The resultant tree implies extensive morphological homoplasy, with many genera emerging as non-monophyletic (Amphibolurus, Rankinia, Ctenophorus, Physignathus, Diporiphora). The water and forest dragons (Physignathus and Hypsilurus) form a paraphyletic basal assemblage to the more derived Australian forms such as Amphibolurus and Ctenophorus, which include almost all the xeric taxa. However, the thorny devil Moloch horridus is a basal lineage and not closely related to the other arid forms. Tree topology, inferred divergence dates, palaeogeographical and palaeoclimatic data are all consistent with Miocene immigration into Australia from the north by mesic forest ecomorphs, followed by initial diversification in mesic habitats before radiation into xeric habitats facilitated by increasing aridity. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 93, 343–358.
TL;DR: Phylogenetic relationships of the family Agamidae were inferred from 860 base positions of a mitochondrial DNA sequence of 12S and 16S rRNA genes and confirmed the monophyly of this family including Leiolepis and Uromastyx, and indicated the sister relationship between Agamids and Chamaeleonidae.
Abstract: Phylogenetic relationships of the family Agamidae were inferred from 860 base positions of a mitochondrial DNA sequence of 12S and 16S rRNA genes. Results confirmed the monophyly of this family including Leiolepis and Uromastyx (Leiolepidinae), and indicated the sister relationship between Agamidae and Chamaeleonidae. Our results also indicated the presence of two major clades in Agamidae. In one of these major clades, “Leiolepidinae” was first diverged, followed by the Lophognathus and Hypsilurus in order, leaving Physignathus, Chlamydosaurus and Pogona as monophyletic. This result contradicts the currently prevailing hypothesis for the agamid phylogeny, which, on the basis of morphological data, assumes the primary dichotomy between Leiolepidinae and the remainder (Agaminae). The phylogenetic diversity of agamid lizards in the Australian region is supposed to have increased through an in situ continental radiation rather than through multiple colonizations from Southeast Asia. Distributions of ...
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Performance Metrics
| Year | Papers |
|---|---|
| 2012 | 1 |
| 2008 | 2 |
| 2000 | 1 |
| 1995 | 1 |