scholarly journals Surface sculpturing in the skull of gecko lizards (Squamata: Gekkota)

2020 ◽  
Vol 131 (4) ◽  
pp. 801-813
Author(s):  
Elizabeth Glynne ◽  
Juan D Daza ◽  
Aaron M Bauer
Keyword(s):  
Phylogenetic Analysis ◽  
Body Size ◽  
Functional Significance ◽  
Evolutionary Transitions ◽  
Apparent Relationship ◽  
Phenotypic Diversification ◽  
Skull Bones

Abstract It has previously been stated that geckos are characterized by smooth cranial bones bearing no sculpturing; however, there are many exceptions. Here we systematically characterize variation in sculpturing in cranial bones across all seven gekkotan families and examine patterns of evolutionary transitions in these traits on a multigene molecular gekkotan phylogeny to elucidate trends in phenotypic diversification in bone sculpturing. Over 195 species were reviewed using specimens where smooth, grooved, pitted and rugose sculpturing patterns were found. Of the 26 cranial bones, only seven (premaxilla, maxilla, nasal, prefrontal, frontal, parietal and postorbitofrontal) were found to bear sculpturing across more than three species. Sculpturing was found to extend beyond these seven bones onto either the dentary, surangular and/or quadrate within five species. Phylogenetic analysis showed that sculpturing evolved recently and repeatedly in several distinct lineages. The remaining 19 skull bones were smooth, except in the five species above, supporting the suggestion that smooth skull bones were ancestral in gekkotans. There is no apparent relationship between body size and the presence of bone sculpturing. The functional significance, if any, of sculpturing requires further investigation.

scholarly journals Phylogenetic analysis of coadaptation in behavior, diet, and body size in the African antelope

2000 ◽  
Vol 11 (4) ◽  
pp. 452-463 ◽  
Author(s):  
Justin S. Brashares ◽  
Theodore Garland ◽  
Peter Arcese
Keyword(s):  
Phylogenetic Analysis ◽  
Body Size

Bursaphelenchus chengi sp. n. (Nematoda: Parasitaphelenchidae) isolated at Nanjing, China, in packaging wood from Taiwan

Nematology ◽  
2008 ◽  
Vol 10 (3) ◽  
pp. 335-346 ◽  
Author(s):  
Hongmei Li ◽  
Phap Quang Trinh ◽  
Lieven Waeyenberge ◽  
Maurice Moens
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Body Size ◽  
Posterior Margin ◽  
Petri Dish ◽  
Packaging Materials ◽  
Lateral Field ◽  
Female Tail ◽  
Domain Sequence ◽  
Lateral Lines

Abstract Bursaphelenchus chengi sp. n. is described and illustrated. Dauer juveniles were isolated from imported wood packaging materials from Taiwan to Nanjing Port, China. Bursaphelenchus chengi sp. n. was reared and maintained on Petri dish cultures of the fungus Botrytis cinerea. The new species is characterised by the medium body size in both sexes, the presence of only two incisures in the lateral field and the robust and strongly curved spicules. The spicule lamina is angular distally, the rostrum digitate and the condylus rounded. The tail is arcuate with a pointed terminus. The bursa is usually truncate with the posterior margin indented in some specimens or rounded with a fine axial point. Females have a small vulval flap formed by a short extension of the cuticle of the anterior lip, and a conical tail that gradually tapers to an almost straight or slightly recurved, pointed or rounded terminus. Because of the presence of two lateral lines, similar spicule shape, tapering female tail and the presence of a small vulval flap, B. chengi sp. n. should be grouped in the abietinus-group sensu Braasch. together with B. abietinus, B. antoniae, B. hellenicus, B. hylobianum and B. rainulfi. ITS-RFLP profiles support the proposal of the new species, and phylogenetic analysis of the 28S rDNA D2/D3 domain sequence places it close to B. antoniae and other species of the abietinus-group.

scholarly journals The functional significance of facultative hyperthermia varies with body size and phylogeny in birds

2019 ◽  
Vol 33 (4) ◽  
pp. 597-607 ◽  
Author(s):  
Alexander R. Gerson ◽  
Andrew E. McKechnie ◽  
Ben Smit ◽  
Maxine C. Whitfield ◽  
Eric K. Smith ◽  
...  
Keyword(s):  
Body Size ◽  
Functional Significance

scholarly journals Solitary ecology as a phenomenon extending beyond insular systems: exaptive evolution in Anolis lizards

2019 ◽  
Vol 15 (5) ◽  
pp. 20190056 ◽  
Author(s):  
Julián A. Velasco ◽  
Steven Poe ◽  
Constantino González-Salazar ◽  
Oscar Flores-Villela
Keyword(s):  
Body Size ◽  
Adaptive Evolution ◽  
Environmental Filtering ◽  
Phenotypic Evolution ◽  
Phenotypic Differentiation ◽  
Evolutionary Transitions ◽  
Ecological Release ◽  
Selective Pressures ◽  
Island Species

The mechanisms driving phenotypic evolution have been of interest to biologists since Darwin. Ecological release—wherein adaptive evolution occurs following relaxation of constraining selective pressures—and environmental filtering—wherein exaptive traits allow colonization of a new area—have been studied in several insular cases. Anolis lizards, which may exist in solitude or sympatry with multiple congeners, are an excellent system for evaluating whether ecological release and environmental filtering are associated with phenotypic shifts across phylogenetic and geographical scales. Insular solitary Anolis exhibit phenotypic differentiation in body size and sexual size dimorphism—SSD—through exaptive and adaptive evolution, respectively. But, the generality of these effects has not yet been addressed. Here, we analyse the evolution of body size and SSD relative to sympatry in mainland Anolis . We found that mainland species co-occurring with few congeners exhibit uniform body size and greater SSD relative to other random mainland assemblages, consistent with the insular solitary pattern. The locations of evolutionary shifts for both traits do not coincide with evolutionary transitions to decreased levels of sympatry. These results are consistent with exaptive environmental filtering but not adaptive ecological release. Future studies should be conducted at local scales to evaluate the role of these factors in the evolution of solitary existence in mainland and island species.

Aphaneramma kokeni (von Huene, 1920), a lonchorhynchine trematosaurid (Amphibia: Temnospondyli) from the Lower Triassic of Pakistan

2020 ◽  
Vol 295 (3) ◽  
pp. 211-241
Author(s):  
Michael W. Maisch
Keyword(s):  
Phylogenetic Analysis ◽  
Lower Triassic ◽  
The Other ◽  
External Exposure ◽  
Nominal Species ◽  
Islamic Republic ◽  
Valid Taxon ◽  
New Diagnosis ◽  
Skull Bones

The type and only known specimen of the lonchorhynchine trematosaurid Aphaneramma kokeni (von Huene, 1920) from the Mianwali Formation (Lower Triassic, Dienerian) of Chiddru, Punjab, Islamic Republic of Pakistan, is redescribed. It is demonstrated that A. kokeni is a valid taxon clearly distinct from other nominal species of the genus and a new diagnosis is provided. The preorbital region of A. kokeni differs considerably from other Aphaneramma species by the small external exposure of the lacrimal, which is almost completely overlapped by the prefrontal, as in some other trematosaurs such as Cosgriffius, Wantzosaurus and Trematolestes. It also differs in the arrangement of the postorbital dermal skull bones, particularly the short postfrontal, lack (or almost so) of a postfrontal-supratemporal contact and the posteriorly extensive frontals, as well as a unique dentition on the ectopterygoid. Phylogenetic analysis places the species in a monophyletic genus Aphaneramma, in a polytomy with the other two nominal species of the genus.

scholarly journals Shrinking dinosaurs and the evolution of endothermy in birds

2020 ◽  
Vol 6 (1) ◽  
pp. eaaw4486 ◽  
Author(s):  
Enrico L. Rezende ◽  
Leonardo D. Bacigalupe ◽  
Roberto F. Nespolo ◽  
Francisco Bozinovic
Keyword(s):  
Heat Transfer ◽  
Body Size ◽  
Energy Requirements ◽  
Transfer Model ◽  
Metabolic Rates ◽  
Evolutionary Transitions ◽  
Thermal Niche ◽  
Stem Lineage ◽  
Major Transition ◽  
Size Data

The evolution of endothermy represents a major transition in vertebrate history, yet how and why endothermy evolved in birds and mammals remains controversial. Here, we combine a heat transfer model with theropod body size data to reconstruct the evolution of metabolic rates along the bird stem lineage. Results suggest that a reduction in size constitutes the path of least resistance for endothermy to evolve, maximizing thermal niche expansion while obviating the costs of elevated energy requirements. In this scenario, metabolism would have increased with the miniaturization observed in the Early-Middle Jurassic (~180 to 170 million years ago), resulting in a gradient of metabolic levels in the theropod phylogeny. Whereas basal theropods would exhibit lower metabolic rates, more recent nonavian lineages were likely decent thermoregulators with elevated metabolism. These analyses provide a tentative temporal sequence of the key evolutionary transitions that resulted in the emergence of small, endothermic, feathered flying dinosaurs.

Genetic diversity of green algal and cyanobacterial photobionts in Nephroma (Peltigerales)

2003 ◽  
Vol 35 (4) ◽  
pp. 325-339 ◽  
Author(s):  
Katileena Lohtander ◽  
Ilona Oksanen ◽  
Jouko Rikkinen
Keyword(s):  
Genetic Diversity ◽  
Phylogenetic Analysis ◽  
Gene Cluster ◽  
Ginkgo Biloba ◽  
Ribosomal Gene ◽  
Ssu Rdna ◽  
Evolutionary Change ◽  
Phylogenetic Groups ◽  
Evolutionary Transitions ◽  
Green Algal

AbstractGenetic diversity of green algal and cyanobacterial photobionts in Nephroma was examined by using nucleotide sequences of the ribosomal gene cluster. The lichens studied included both bipartite and tripartite species. There was very little variation in green algal-ITS sequences of N. arcticum and N. expallidum. Almost identical sequences were obtained from all thalli analysed and also from two tripartite Peltigera species. On the basis of SSU rDNA data the green algal photobionts of N. arcticum are closely related to the primary photobiont of P. britannica, and also to an endophytic alga of Ginkgo biloba. The SSU rDNA region of lichen-forming cyanobacteria was rather variable. A phylogenetic analysis indicated that the Nostoc specimens formed a monophyletic group and the strains were divided into two main groups. One clade included only cyanobionts of lichens, including those of all bipartite Nephroma species. The second group was genetically more heterogeneous and included mainly cyanobionts of terricolous cyanolichens, including those of both tripartite Nephroma species studied. The distinction between bi- and tripartite Nephroma species is significant as the mycobionts of tripartite species are not monophyletic. It implies that within Nephroma, evolutionary transitions between symbiosis types cannot have been achieved simply via an acquisition or loss of the green algal photobiont. As the Nostoc symbionts of bi- and tripartite species belong to different phylogenetic groups, an evolutionary change in green algal association has required a concurrent change in cyanobiont composition.

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