Some recent non-dino papers and stuff...
Roger A. Close, Roger B. J. Benson, John Alroy, Anna K. Behrensmeyer, Juan Benito, Matthew T. Carrano, Terri J. Cleary, Emma M. Dunne, Philip D. Mannion, Mark D. Uhen & Richard J. Butler (2019)
Diversity dynamics of Phanerozoic terrestrial tetrapods at the local-community scale.
Nature Ecology & Evolution ISSN 2397-334X
The fossil record provides one of the strongest tests of the hypothesis that diversity within local communities is constrained over geological timescales. Constraints to diversity are particularly controversial in modern terrestrial ecosystems, yet long-term patterns are poorly understood. Here we document patterns of local richness in Phanerozoic terrestrial tetrapods using a global data set comprising 145,332 taxon occurrences from 27,531 collections. We show that the local richness of non-flying terrestrial tetrapods has risen asymptotically since their initial colonization of land, increasing at most threefold over the last 300 million years. Statistical comparisons support phase-shift models, with most increases in local richness occurring: (1) during the colonization of land by vertebrates, concluding by the late Carboniferous; and (2) across the Cretaceous/Paleogene boundary. Individual groups, such as mammals, lepidosaurs and dinosaurs also experienced early increases followed by periods of stasis often lasting tens of millions of years. Mammal local richness abruptly tripled across the Cretaceous/Paleogene boundary, but did not increase over the next 66 million years. These patterns are consistent with the hypothesis that diversity is constrained at the local-community scale.
News:
Diversity on land is not higher today than in the past, study shows
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Banhxeochelys trani gen. et sp. nov.ÂÂ
Rafaella C. Garbin, Madelaine BÃhme & Walter G. Joyce (2019)
A new testudinoid turtle from the middle to late Eocene of Vietnam.
PeerJ 7:e6280
Free pdf:
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Background
Testudinoidea is a major clade of turtles that has colonized different ecological environments across the globe throughout the Tertiary. Aquatic testudinoids have a particularly rich fossil record in the Tertiary of the northern hemisphere, but little is known about the evolutionary history of the group, as the phylogenetic relationships of most fossils have not been established with confidence, in part due to high levels of homoplasy and polymorphism.
Methods
We here focus on describing a sample of 30 testudinoid shells, belonging to a single population that was collected from lake sediments from the middle to late Eocene (35â39 Ma) Na Duong Formation in Vietnam. The phylogenetic placement of this new material is investigated by integrating it and 11 other species of putative geoemydids from the Eocene and Oligocene to a recently published matrix of geoemydid turtles, that embraces the use of polymorphic characters, and then running a total-evidence analysis.
Results
The new material is highly polymorphic, but can be inferred with confidence to be a new taxon, Banhxeochelys trani gen. et sp. nov. It shares morphological similarities with other southeastern Asian testudinoids, Isometremys lacuna and Guangdongemys pingi, but is placed phylogenetically at the base of Pan-Testuguria when fossils are included in the analysis, or as a stem geoemydid when other fossils are deactivated from the matrix. The vast majority of other putative fossil geoemydids are placed at the base of Pan-Testuguria as well.
Discussion
The phylogenetic placement of fossil testudinoids used in the analysis is discussed individually and each species compared to Banhxeochelys trani gen. et sp. nov. The high levels of polymorphism observed in the new taxon is discussed in terms of ontogenetic and random variability. This is the first time that a large sample of fossil testudinoids has its morphological variation described in detail.
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Abigail Lind, Yvonne Y.Y. Lai, Yulia Mostovoy, Alisha K Holloway, Alessio Iannucci, Angel CY Mak, Marco Fondi, Valerio Orlandini, Walter L Eckalbar, Massimo Milan, Michail Rovatsos, Ilya G. Kichigin, Alex I Makunin, Vladimir Trifonov, Elio Schijlen, Lukas Kratochvil, Renato Fani, Tim S Jessop, Tomaso Patarnello, James W Hicks, Oliver A. Ryder, Joseph R. Mendelson III, Claudio Ciofi, Pui-Yan A. Kwok, Katherine S Pollard & Benoit Bruneau (2019)
A high-resolution, chromosome-assigned Komodo dragon genome reveals adaptations in the cardiovascular, muscular, and chemosensory systems of monitor lizards.
bioRxiv 551978Â
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Monitor lizards are unique among ectothermic reptiles in that they have a high aerobic capacity and distinctive cardiovascular physiology which resembles that of endothermic mammals. We have sequenced the genome of the Komodo dragon (Varanus komodoensis), the largest extant monitor lizard, and present a high resolution de novo chromosome-assigned genome assembly for V. komodoensis, generated with a hybrid approach of long-range sequencing and single molecule physical mapping. Comparing the genome of V. komodoensis with those of related species showed evidence of positive selection in pathways related to muscle energy metabolism, cardiovascular homeostasis, and thrombosis. We also found species-specific expansions of a chemoreceptor gene family related to pheromone and kairomone sensing in V. komodoensis and several other lizard lineages. Together, these evolutionary signatures of adaptation reveal genetic underpinnings of the unique Komodo sensory, cardiovascular, and muscular systems, and suggest that selective pressure altered thrombosis genes to help Komodo dragons evade the anticoagulant effects of their own saliva. As the only sequenced monitor lizard genome, the Komodo dragon genome is an important resource for understanding the biology of this lineage and of reptiles worldwide.
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Arjan Mann, Jennifer C. Olori & Hillary C. Maddin (2019)
Postcranial anatomy of the 'microsaur' Carrolla craddocki from the Lower Permian of Texas.
Journal of Vertebrate Paleontology Article: e1532436
[no abstract]
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Abstract only for now....
Bryan M. Gee, Joseph J. Bevitt and Roberto R. Reisz (2019)
A juvenile specimen of the trematopid Acheloma from Richards Spur, Oklahoma and challenges of trematopid ontogeny.
Frontiers in Earth Science (abstract only for now...)
doi: 10.3389/feart.2019.00038
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Trematopids are a clade of terrestrial dissorophoid temnospondyls documented primarily from terrestrial Permo-Carboniferous environments in North America and Europe. Here we describe the complete skull and articulated mandibles of a diminutive trematopid specimen (OMNH 79318) from the Early Permian karst deposits near Richards Spur, Oklahoma. Based on aspects of the neurocranium (e.g., unossified sphenethmoid, prootics, epipterygoids), the specimen represents one of the best examples of a markedly immature trematopid, an important data point for understanding the early ontogeny of trematopids. Specifically, it provides evidence that variation in otic notch structure can be ontogenetically influenced, not only among eucacopine dissorophids but also among trematopids. We provisionally refer the specimen to cf. Acheloma based on the presence of a denticulate vomerine ridge and other qualitative features. However, we emphasize that the taxonomic referral is complicated by several factors that more broadly confound trematopid taxonomy. This includes a low sample size (n = 1) of many taxa and marked size, and presumed ontogenetic, disparity between the known size range of different taxa. Complementary reexamination of both Acheloma cumminsi and Acheloma dunni as part of this study also reveals that the former possesses lateral exposures of palate bones, the presence / absence of which was the only formal character that previously differentiated the two species, although other qualitative features (e.g., size of the internarial fontanelle) may differentiate these two species. With respect to OMNH 79318, the taxonomic referral is tentative because the specimen also shares many qualitative attributes with Phonerpeton pricei, a trematopid represented only by small-bodied, probably immature individuals. However, many of these shared features are likely to be influenced by ontogeny or size. The subsequent challenges that we encountered in our taxonomic referral suggest that ontogeny may be confounding taxonomy in both diagnoses and phylogenetic analyses of trematopids and emphasize the need for careful study of how this affects our understanding of trematopid intrarelationships.