Ben Creisler
New papers:
Itapecuruemys amazonensis gen. et sp. nov.
Diogo Lins Batista, Ismar de Souza Carvalho & Marcelo S. de la Fuente (2020)
A new Cretaceous (Pleurodira:Pelomedusoides) from the Lower Cretaceous of ParnaÃba Basin, Brazil.
Journal of South American Earth Sciences 102872 (advance online publication)
doi:
https://doi.org/10.1016/j.jsames.2020.102872https://www.sciencedirect.com/science/article/abs/pii/S0895981120304156Highlights
A new species of Pleurodira for the Itapecuru Formation, ParnaÃba Basin, CretÃeo Inferior.
Different morphological structure can be observed in the neural series in this new species.
Chelonian with different morphological characteristics from Araripemys barretoi allows a diversity of environments.
They are important to the reconstruction of the terrestrial Cretaceous ecosystem in the context of the ParnaÃba Basin.
Abstract
The new Pleurodira turtle Itapecuruemys amazonensis gen. et sp. nov. from the Itapecuru Formation (ParnaÃba Basin, Brazil) is described. The new species is represented only by its holotype, which consists of an almost complete carapace and plastron, with an oval-shaped outline. The most peculiar characters of Itapecuruemys amazonensis are: neural plates six and seven are separated by costal six, and the seventh neural plate contacts the sixth, seventh and eighth costal plates and a suprapygal. The phylogenetic hypothesis proposed in this paper suggests that Itapecuruemys amazonensis, together with Cerachelys and Galianemys spp., form a monophyletic assemblage and also widen the paleoherpetological diversity of the Itapecuru Formation in the ParnaÃba Basin (Brazil).
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Brooke L. Bodensteiner, ÂGustavo A. AgudeloâCantero, ÂA. Z. Andis Arietta, ÂAlex R. Gunderson, ÂMartha M. MuÃoz, ÂJeanine M. Refsnider & Eric J. Gangloff (2020)
Thermal adaptation revisited: How conserved are thermal traits of reptiles and amphibians?
doi:
https://doi.org/10.1002/jez.2414https://onlinelibrary.wiley.com/doi/10.1002/jez.2414Ectothermic animals, such as amphibians and reptiles, are particularly sensitive to rapidly warming global temperatures. One response in these organisms may be to evolve aspects of their thermal physiology. If this response is adaptive and can occur on the appropriate time scale, it may facilitate population or species persistence in the changed environments. However, thermal physiological traits have classically been thought to evolve too slowly to keep pace with environmental change in longerâlived vertebrates. Even as empirical work of the midâ20th century offers mixed support for conservatism in thermal physiological traits, the generalization of low evolutionary potential in thermal traits is commonly invoked. Here, we revisit this hypothesis to better understand the mechanisms guiding the timing and patterns of physiological evolution. Characterizing the potential interactions among evolution, plasticity, behavior, and ontogenetic shifts in thermal physiology is critical for accurate prediction of how organisms will respond to our rapidly warming world. Recent work provides evidence that thermal physiological traits are not as evolutionarily rigid as once believed, with many examples of divergence in several aspects of thermal physiology at multiple phylogenetic scales. However, slow rates of evolution are often still observed, particularly at the warm end of the thermal performance curve. Furthermore, the contextâspecificity of many responses makes broad generalizations about the potential evolvability of traits tenuous. We outline potential factors and considerations that require closer scrutiny to understand and predict reptile and amphibian evolutionary responses to climate change, particularly regarding the underlying genetic architecture facilitating or limiting thermal evolution.
Research Highlights
Here, we review how interactions among evolution, plasticity, behavior, and ontogeny shape thermal physiological traits in reptiles and amphibians, finding that these traits are not as evolutionarily rigid as once believed across phylogenetic scales.
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This study compares several geochemical factors (major and minor rare earth elements, Ti/Al ratios, and chemical index of alteration, CIA, values) in the Early Triassic CaÃizar Formation (Fm) (Buntsandtein facies) of E Iberia with those of adjacent Middle Permian and Middle Triassic units (Alcotas and Eslida fms, respectively). According to significant differences detected, it seems that most geochemical perturbation occurred during the Early Triassic. Variations in Ti/Al ratios suggest changes in source areas between the studied units and even within the CaÃizar Fm. These provenance changes correlate with successive tectonic pulses during the opening and development of the Iberian Basin, as they can be linked to major sedimentary surfaces and unconformities, as well as major sedimentological variations. Ti enrichment in the lower and middle part of the CaÃizar Fm, together with high Sr and P concentrations, may be indicative of environmental alterations related to acid meteoric waters. Moreover, this acid alteration took place under arid conditions as reflected by CIA values, indicating that during the deposition of the CaÃizar Fm, variable but predominantly physical weathering prevailed in contrast to the chemical weathering that took place when the Alcotas and Eslida formations were deposited. Our data along with the known fossil record of the study area indicate that during the MiddleâLate Permian and Early Triassic, conditions in this tectonically active area changed from humid to arid-acid, hampering biotic recovery. Then, during late EarlyâMiddle Triassic times, the return of more humid and less acid environments promoted biotic development. Geochemical markers emerged as useful tools complementary to sedimentological, paleontological, and tectonic data for unveiling paleoenvironmental events, especially in a setting of significant regional change.