A Total-Group Phylogenetic Metatree for Cetacea and the Importance of Fossil Data in Diversification Analyses

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2020, Номер unknown

Опубликована: Июнь 25, 2020

A bstract Phylogenetic trees provide a powerful framework for testing macroevolutionary hypotheses, but it is becoming increasingly apparent that inferences derived from extant species alone can be highly misleading. Trees incorporating living and extinct taxa are needed to address fundamental questions about the origins of diversity disparity has proved challenging generate robust, species–rich phylogenies include large numbers fossil taxa. As result, most studies diversification dynamics continue rely on molecular phylogenies. Here, we extend apply recently developed meta–analytic approach synthesizing previously published phylogenetic infer well–resolved set level, time–scaled hypotheses cetaceans (whales, dolphins allies). Our sampling ∼ 90 over 400 species, therefore allow more robust inference dynamics. While scenarios recover broadly concordant with those inferred they differ in critical ways, notably relative contributions extinction speciation rate shifts driving rapid radiations. Supertrees often viewed as poor substitute directly character data metatree pipeline overcomes many past criticisms leveled at these approaches. Meta–analytic immediate route integrating fossils into analyses, results which range untrustworthy nonsensical without them.

Язык: Английский

---

Diuqin lechiguanae gen. et sp. nov., a new unenlagiine (Theropoda: Paraves) from the Bajo de la Carpa Formation (Neuquén Group, Upper Cretaceous) of Neuquén Province, Patagonia, Argentina

BMC Ecology and Evolution, Год журнала: 2024, Номер 24(1)

Опубликована: Июнь 14, 2024

Abstract Background Unenlagiine paravians are among the most relevant Gondwanan theropod dinosaur clades for understanding origin of birds, yet their fossil record remains incomplete, with taxa being represented by fragmentary material and/or separated lengthy temporal gaps, frustrating attempts to characterize unenlagiine evolution. Results and conclusions Here we describe Diuqin lechiguanae gen. et sp. nov., a new taxon from Upper Cretaceous (Santonian) Bajo de la Carpa Formation Neuquén Basin Province in northern Patagonia, Argentina that fills substantial stratigraphic gap these theropods. Although known only very incomplete postcranial skeleton, preserved bones differ corresponding elements other unenlagiines, justifying erection taxon. Moreover, several morphological aspects, humerus appears intermediate between those geologically older unenlagiines (e.g., Unenlagia spp. Turonian–Coniacian Portezuelo Formation) stratigraphically younger, larger-bodied Austroraptor cabazai Campanian–Maastrichtian Allen Formation. Consequently, morphology indicate transitional stage Phylogenetic analysis recovers as paravian multiple plausible systematic positions, but strongest affinity is Unenlagiinae. The form exhibits subcircular punctures near its distal end interpreted feeding traces likely left conical-toothed crocodyliform, mammal, or theropod, latter potentially megaraptorid another individual. Thus, addition filling important gaps evolutionary history, also offers information relating paleoecology

Язык: Английский

---

Body size and evolutionary rate analyses reveal complex evolutionary history of Alvarezsauria

Cladistics, Год журнала: 2024, Номер unknown

Опубликована: Дек. 11, 2024

Some of the smallest examples dinosaurian body size are from alvarezsaurians, an enigmatic group maniraptoran coelurosaurians with a peculiar combination anatomical features unique among theropods. Despite large number alvarezsaurian species described worldwide and increased understanding this has provided, body-size macroevolution alvarezsaurians received little attention. Here we reconstruct analyse directional trends evolution through integrated analysis mass, ontogenetic age, morphological rate data enabled by comprehensively revised phylogeny. Our analyses identify four periods high (Bathonian-Callovian, Hauterivian-early Berriasian, early Cenomanian, late Cenomanian-Turonian) that link to key effects animal changes for first time, including novelty, structural reduction simplification, elevated homoplasy, behavioral associated miniaturization. In doing so, study provides holistic example miniaturization in Mesozoic vertebrate offers framework other detailed studies evolution, more disparate groups.

Язык: Английский

---

The first juvenile dromaeosaurid (Dinosauria: Theropoda) from Arctic Alaska

PLoS ONE, Год журнала: 2020, Номер 15(7), С. e0235078 - e0235078

Опубликована: Июль 8, 2020

Compared to the osteological record of herbivorous dinosaurs from Late Cretaceous Prince Creek Formation northern Alaska, there are relatively fewer remains theropods. The theropod this unit is mostly comprised isolated teeth, and only non-dental known can be attributed troodontid cf. Troodon tyrannosaurid Nanuqsaurus. Thus far, presence members Dromaeosauridae has been limited teeth. Here we describe a symphyseal portion small dentary with two ziphodont Based on tooth shape, denticle morphology, position Meckelian groove, attribute partial saurornitholestine dromaeosaurid. fibrous bone surface, size, higher number mesial denticles compared distal ones point juvenile growth stage for individual. Multivariate comparison teeth morphospace by means principal component analysis reveals an overlap between Saurornitholestinae dromaeosaurid morphospace, result supported phylogenetic analyses. This first confirmed fossil specimen member in Arctic, expanding role Beringia as dispersal route clade Asia North America. Furthermore, nature individual adds growing body data that suggests Arctic Alaska did not undergo long-distance migration, but rather they were year-round residents these paleopolar latitudes.

Язык: Английский

---

Preserved soft anatomy confirms shoulder-powered upstroke of early theropod flyers, reveals enhanced early pygostylian upstroke, and explains early sternum loss

Proceedings of the National Academy of Sciences, Год журнала: 2022, Номер 119(47)

Опубликована: Ноя. 14, 2022

Anatomy of the first flying feathered dinosaurs, modern birds and crocodylians, proposes an ancestral flight system divided between shoulder chest muscles, before upstroke muscles migrated beneath body. This featured dorsally positioned deltoids supracoracoideus controlling chest-bound pectoralis downstroke. Preserved soft anatomy is needed to contextualize origin system, but this has remained elusive. Here we reveal earliest theropod flyers preserved as residual skin chemistry covering body delimiting its margins. These data provide that independently validate system. The heavily constructed more weakly in early pygostylian Confuciusornis indicated by a profile, upstroke-enhanced stroke. Slender ventral profiles early-diverging Archaeopteryx Anchiornis suggest habitual use could not maintain sternum through bone functional adaptations. Increased wing-assisted terrestrial locomotion potentially accelerated loss higher breathing requirements. Lower expected downstroke requirements thermal soarer Sapeornis have driven adaption, possibly encouraged demands Confuciusornis-like upstroke. Both factors are supported slender profile. shoulder/chest insights into novel strokes loss, filling important gaps our understanding appearance flight.

Язык: Английский

---