The earliest equatorial record of frogs from the Late Triassic of Arizona

Stocker, Michelle R.; Nesbitt, Sterling J.; Kligman, Ben T.; Paluh, Daniel J.; Marsh, Adam D.; Blackburn, David C.; Parker, William G.

doi:10.1098/rsbl.2018.0922

Cited by 36 publications

(24 citation statements)

References 24 publications

(34 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The identification of Triassurus as a urodele predates the latest time window for the dispersal of stem-salamanders before the marine ingression into Europe and currently indicates Inner Asia as the place of origin of the salamander lineage, which is consistent with earlier vicariance hypotheses (34). Batrachian stem taxa are known from North America and Europe, whereas salientians evidently dispersed rapidly to Europe (6), North America (35), and southern Gondwana (Madagascar). Thus, batrachians are likely to have originated in the Early Permian somewhere in the Variscian mountain belt, with frog ancestors extending southward into Gondwana and salamander ancestors eastward into Inner Asia.…”

Section: Resultsmentioning

confidence: 99%

A Triassic stem-salamander from Kyrgyzstan and the origin of salamanders

Schoch

Werneburg

Voigt³

2020

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The origin of extant amphibians remains largely obscure, with only a few early Mesozoic stem taxa known, as opposed to a much better fossil record from the mid-Jurassic on. In recent time, anurans have been traced back to Early Triassic forms and caecilians have been traced back to the Late JurassicEocaecilia, both of which exemplify the stepwise acquisition of apomorphies. Yet the most ancient stem-salamanders, known from mid-Jurassic rocks, shed little light on the origin of the clade. The gap between salamanders and other lissamphibians, as well as Paleozoic tetrapods, remains considerable. Here we report a new specimen ofTriassurus sixtelae, a hitherto enigmatic tetrapod from the Middle/Late Triassic of Kyrgyzstan, which we identify as the geologically oldest stem-group salamander. This sheds light not only on the early evolution of the salamander body plan, but also on the origin of the group as a whole. The new, second specimen is derived from the same beds as the holotype, the Madygen Formation of southwestern Kyrgyzstan. It reveals a range of salamander characters in this taxon, pushing back the rock record of urodeles by at least 60 to 74 Ma (Carnian–Bathonian). In addition, this stem-salamander shares plesiomorphic characters with temnospondyls, especially branchiosaurids and amphibamiforms.

show abstract

Section: Resultsmentioning

confidence: 99%

A Triassic stem-salamander from Kyrgyzstan and the origin of salamanders

Schoch

Werneburg

Voigt³

2020

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…During the Late Triassic, sudden paleoenvironmental events include reoccurring flood basalt volcanism such as the Wrangellia Large Igneous Province (Greene et al, 2010, and references within) and the Central Atlantic Magmatic Province (Whiteside et al, 2010;Schoene et al, 2010;Blackburn et al, 2013), as well as at least three hypervelocity impact events, the largest of which is the Manicouagan impact structure in Canada (Ramezani et al, 2005;Grieve, 2006;Schmieder et al, 2010Schmieder et al, , 2014Cohen et al, 2017). At the same time, the Late Triassic witnessed a number of important evolutionary events, such as the origin and early diversification of dinosaurs, lizards, mammaliaforms, and lissamphibians on land, and the diversification of scleractinian corals and calcareous nannoplankton in the ocean (e.g., Rogers et al, 1993;Stanley, 2003;Falkowski et al, 2004;Furin et al, 2006;Luo, 2007;Irmis, 2011;Fraser and Sues, 2011;Stocker et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

U-Pb zircon geochronology and depositional age models for the Upper Triassic Chinle Formation (Petrified Forest National Park, Arizona, USA): Implications for Late Triassic paleoecological and paleoenvironmental change

et al. 2020

Self Cite

View full text Add to dashboard Cite

The Upper Triassic Chinle Formation is a critical non-marine archive of low-paleolatitude biotic and environmental change in southwestern North America. The well-studied and highly fossiliferous Chinle strata at Petrified Forest National Park (PFNP), Arizona, preserve a biotic turnover event recorded by vertebrate and palynomorph fossils, which has been alternatively hypothesized to coincide with tectonically driven climate change or with the Manicouagan impact event at ca. 215.5 Ma. Previous outcrop-based geochronologic age constraints are difficult to put in an accurate stratigraphic framework because lateral facies changes and discontinuous outcrops allow for multiple interpretations. A major goal of the Colorado Plateau Coring Project (CPCP) was to retrieve a continuous record in unambiguous superposition designed to remedy this situation. We sampled the 520-m-long core 1A of the CPCP to develop an accurate age model in unquestionable superposition by combining U-Pb zircon ages and magnetostratigraphy. From 13 horizons of volcanic detritus-rich siltstone and sandstone, we screened up to ∼300 zircon crystals per sample using laser ablation−inductively coupled plasma−mass spectrometry and subsequently analyzed up to 19 crystals of the youngest age population using the chemical abrasion−isotope dilution−thermal ionization mass (CA-ID-TIMS) spectrometry method. These data provide new maximum depositional ages for the top of the Moenkopi Formation (ca. 241 Ma), the lower Blue Mesa Member (ca. 222 Ma), and the lower (ca. 218 to 217 Ma) and upper (ca. 213.5 Ma) Sonsela Member. The maximum depositional ages obtained for the upper Chinle Formation fall well within previously proposed age constraints, whereas the maximum depositional ages for the lower Chinle Formation are relatively younger than previously proposed ages from outcrop; however, core to outcrop stratigraphic correlations remain uncertain. By correlating our new ages with the magnetostratigraphy of the core, two feasible age model solutions can be proposed. Model 1 assumes that the youngest, coherent U-Pb age clusters of each sample are representative of the maximum depositional ages and are close to (<1 Ma difference) the true time of deposition throughout the Sonsela Member. This model suggests a significant decrease in average sediment accumulation rate in the mid-Sonsela Member. Hence, the biotic turnover preserved in the mid-Sonsela Member at PFNP is also middle Norian in age, but may, at least partially, be an artifact of a condensed section. Model 2 following the magnetostratigraphic-based age model for the CPCP core 1A suggests instead that the ages from the lower and middle Sonsela Member are inherited populations of zircon crystals that are 1−3 Ma older than the true depositional age of the strata. This results in a model in which no sudden decrease in sediment accumulation rate is necessary and implies that the base of the Sonsela Member is no older than ca. 216 Ma. Independent of these alternatives, both age models agree that none of the preserved Chinle Formation in PFNP is Carnian (>227 Ma) in age, and hence the biotic turnover event cannot be correlated to the Carnian−Norian boundary but is rather a mid-Norian event. Our age models demonstrate the powers, but also the challenges, of integrating detrital CA-ID-TIMS ages with magnetostratigraphic data to properly interpret complex sedimentary sequences.

show abstract

“…Remarkably, no salientians at all have so far been reported from the Yanliao Biota (Haifanggou, Lanqi, Tiaojishan and maybe other formations of Callovian to Oxfordian age in northeastern China), despite its wealth of salamanders (see node 169). The stem-salientian record is sparse (Marjanović and Laurin, 2013b; Stocker et al, 2019); the suggestion of a maximum age for Bombinanura of 170 to 185 Ma by Marjanović and Laurin (2013b) is based on the fairly good stratigraphic fit of stem-salientian phylogeny (Marjanović and Laurin, 2007, 2013a: fig. 5, 2013b; Stocker et al, 2019; and references therein), but given its poor geographic coverage, I prefer to follow Irisarri et al (2017) in not assigning a maximum age other than that of node 160 for present purposes.…”

Section: Methodsmentioning

confidence: 99%

The making of calibration sausage exemplified by recalibrating the transcriptomic timetree of jawed vertebrates

Marjanović

2019

Preprint

View full text Add to dashboard Cite

9Molecular divergence dating has the potential to overcome the incompleteness of the fossil record in 10 inferring when cladogenetic events (splits, divergences) happened, but needs to be calibrated by the 11 fossil record. Ideally but unrealistically, this would require practitioners to be specialists in molecular 12 evolution, in the phylogeny and the fossil record of all sampled taxa, and in the chronostratigraphy of 13 the sites the fossils were found in. Paleontologists have therefore tried to help by publishing 14 compendia of recommended calibrations, and molecular biologists unfamiliar with the fossil record 15have made heavy use of such works. Using a recent example of a large timetree inferred from 16 molecular data, I demonstrate that calibration dates cannot be taken from published compendia 17 without risking strong distortions to the results, because compendia become outdated faster than they 18 are published. The present work cannot serve as such a compendium either; in the slightly longer 19 term, it can only highlight known and overlooked problems. Future authors will need to solve each of 20 these problems anew through a thorough search of the primary paleobiological and 21 chronostratigraphic literature on each calibration date every time they infer a new timetree; over 40% 22 of the sources I cite were published after mid-2016. 23 Treating all calibrations as soft bounds results in younger nodes than treating all calibrations as hard 24bounds. The unexpected exception are nodes calibrated with both minimum and maximum ages, 25 further demonstrating the widely underestimated importance of maximum ages in divergence dating. 26

show abstract

The earliest equatorial record of frogs from the Late Triassic of Arizona

Cited by 36 publications

References 24 publications

A Triassic stem-salamander from Kyrgyzstan and the origin of salamanders

A Triassic stem-salamander from Kyrgyzstan and the origin of salamanders

U-Pb zircon geochronology and depositional age models for the Upper Triassic Chinle Formation (Petrified Forest National Park, Arizona, USA): Implications for Late Triassic paleoecological and paleoenvironmental change

The making of calibration sausage exemplified by recalibrating the transcriptomic timetree of jawed vertebrates

Contact Info

Product

Resources

About