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Journal articles on the topic 'Dinosaurs - Phylogeny'

Author: Grafiati

Published: 4 June 2021

Last updated: 8 February 2022

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1

Seebacher, Frank. "Dinosaur body temperatures: the occurrence of endothermy and ectothermy." Paleobiology 29, no. 1 (2003): 105–22. http://dx.doi.org/10.1666/0094-8373(2003)029<0105:dbttoo>2.0.co;2.

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Despite numerous studies, the thermal physiology of dinosaurs remains unresolved. Thus, perhaps the commonly asked question whether dinosaurs were ectotherms or endotherms is inappropriate, and it is more constructive to ask which dinosaurs were likely to have been endothermic and which ones ectothermic. Field data from crocodiles over a large size range show that body temperature fluctuations decrease with increasing body mass, and that average daily body temperatures increase with increasing mass. A biophysical model, the biological relevance of which was tested against field data, was used to predict body temperatures of dinosaurs. However, rather than predicting thermal relations of a hypothetical dinosaur, the model considered correct paleogeographical distribution and climate to predict the thermal relations of a large number of dinosaurs known from the fossil record (>700). Many dinosaurs could have had “high” (>30°) and stable (daily amplitude >2°) body temperatures without metabolic heat production even in winter, so it is unlikely that selection pressure would have favored the evolution of elevated resting metabolic rates in those species. Recent evidence of ontogenetic growth rates indicates that even the juveniles of large species (3000–4000 kg) could have had biologically functional body temperature ranges during early development. Smaller dinosaurs (<100 kg) at mid to high latitudes (>45°) could not have had high and stable body temperatures without metabolic heat production. However, elevated metabolic rates were unlikely to have provided selective advantage in the absence of some form of insulation, so probably insulation was present before endothermy evolved, or else it coevolved with elevated metabolic rates. Superimposing these findings onto a phylogeny of the Dinosauria suggests that endothermy most likely evolved among the Coelurosauria and, to a lesser extent, among the Hypsilophodontidae, but not among the Stegosauridae, Nodosauridae, Ankylosauridae, Hadrosauridae, Ceratopsidae, Prosauropoda, and Sauropoda.

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2

Benson, Roger B. J. "Dinosaur Macroevolution and Macroecology." Annual Review of Ecology, Evolution, and Systematics 49, no. 1 (November 2, 2018): 379–408. http://dx.doi.org/10.1146/annurev-ecolsys-110617-062231.

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Dinosaurs were large-bodied land animals of the Mesozoic that gave rise to birds. They played a fundamental role in structuring Jurassic–Cretaceous ecosystems and had physiology, growth, and reproductive biology unlike those of extant animals. These features have made them targets of theoretical macroecology. Dinosaurs achieved substantial structural diversity, and their fossil record documents the evolutionary assembly of the avian body plan. Phylogeny-based research has allowed new insights into dinosaur macroevolution, including the adaptive landscape of their body size evolution, patterns of species diversification, and the origins of birds and bird-like traits. Nevertheless, much remains unknown due to incompleteness of the fossil record at both local and global scales. This presents major challenges at the frontier of paleobiological research regarding tests of macroecological hypotheses and the effects of dinosaur biology, ecology, and life history on their macroevolution.

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3

Butler, Richard J., Paul Upchurch, and David B. Norman. "The phylogeny of the ornithischian dinosaurs." Journal of Systematic Palaeontology 6, no. 1 (January 2008): 1–40. http://dx.doi.org/10.1017/s1477201907002271.

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4

Brownstein, Chase Doran. "Osteology and phylogeny of small-bodied hadrosauromorphs from an end-Cretaceous marine assemblage." Zoological Journal of the Linnean Society 191, no. 1 (August 15, 2020): 180–200. http://dx.doi.org/10.1093/zoolinnean/zlaa085.

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Abstract The timing of non-avian dinosaur decline is one of the most debated subjects in dinosaur palaeontology. Dinosaur faunas from the last few million years of the Mesozoic appear far less diverse than those from earlier in the Cretaceous, a trend that could suggest non-avian dinosaur extinction occurred gradually. However, the limited nature of the latest Cretaceous dinosaur record outside western North America has obscured patterns in dinosaur diversity just before the extinction. Here, I describe two associated skeletons and several isolated fossils recovered from the New Egypt Formation of New Jersey, a latest Maastrichtian unit that underlies the K–Pg boundary. The larger skeleton appears to be a small-bodied adult from a lineage outside Hadrosauridae, the dominant group of these animals during the Maastrichtian, that persisted along the eastern coast of North America. Smaller specimens are identifiable as juvenile hadrosauromorphs. These results substantiate an important assemblage of herbivorous dinosaurs from the poorly-known Cretaceous of eastern North America. The marine depositional setting for these skeletons demonstrates that proposed ecosystem preferences among hadrosauromorphs may be biased by post-mortem transportation, and the adult skeleton has implications for assessing the proposed relictual nature of Late Cretaceous eastern North American vertebrates.

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Thompson, Richard S., Jolyon C. Parish, Susannah C. R. Maidment, and Paul M. Barrett. "Phylogeny of the ankylosaurian dinosaurs (Ornithischia: Thyreophora)." Journal of Systematic Palaeontology 10, no. 2 (June 30, 2011): 301–12. http://dx.doi.org/10.1080/14772019.2011.569091.

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6

Arbour, Victoria M., and Philip J. Currie. "Systematics, phylogeny and palaeobiogeography of the ankylosaurid dinosaurs." Journal of Systematic Palaeontology 14, no. 5 (July 28, 2015): 385–444. http://dx.doi.org/10.1080/14772019.2015.1059985.

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7

Kubo, Tai. "Biogeographical Network Analysis of Cretaceous Terrestrial Tetrapods: A Phylogeny-Based Approach." Systematic Biology 68, no. 6 (May 27, 2019): 1034–51. http://dx.doi.org/10.1093/sysbio/syz024.

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Abstract Network methods are widely used to represent and analyze biogeography. It is difficult, however, to convert occurrence data of fossil vertebrates to a biogeographical network, as most species were known from a single locality. A new method for creating a biogeographical network that can incorporate phylogenetic information is proposed in this study, which increases the number of edges in the network of fossil vertebrates and enables the application of various network methods. Using ancestral state reconstruction via maximum parsimony, the method first estimates the biogeographical regions of all internal nodes of a given phylogeny using biogeographical information on the terminal taxa. Then, each internal node in the phylogenetic tree is converted to an edge in the biogeographical network that connects the region(s), if unambiguously estimated, of its two descendants. The new method was applied to phylogenetic trees generated by a birth–death model. Under all conditions tested, an average of $CDATA[$CDATA[$>$$70% of the internal nodes in phylogenetic trees were converted into edges. Three network indices—link density, average link weight, and endemism index (EI)—were evaluated for their usefulness in comparing different biogeographical networks. The EI reflects the rate of dispersal; the other indices reflect nonbiogeographical parameters, the number of taxa and regions, which highlights the importance of evaluating network indices before applying them to biogeographical studies. Multiple Cretaceous biogeographical networks were constructed from the phylogenies of five tetrapod taxa: terrestrial crocodyliforms, terrestrial turtles, nonavian dinosaurs, avians, and pterosaurs. The networks of avians and pterosaurs showed similar topologies and a strong correlation, and unexpectedly high endemism indices. These similarities were probably a result of shared taphonomic biases (i.e., the Lagerstätten effect) for volant taxa with fragile skeletons. The crocodyliform network was partitioned into the Gondwanan and Laurasian continents. The dinosaur network was partitioned into three groups of continents: 1) North America, Asia, and Australia; 2) Europe and Africa; and 3) India, Madagascar, and South America. When Early and Late Cretaceous dinosaurs were analyzed separately, the dinosaur networks were divided into 1) North America, Asia, and Australia; and 2) Europe, Africa, India, and South America for the Early Cretaceous and 1) North America, Asia, and Europe; and 2) India, Madagascar, and South America for the Late Cretaceous. This partitioning of dinosaur and crocodyliform networks corroborates the results of previous biogeographical studies and indicates that the method introduced here can retrieve biogeographical signals from a source phylogeny when sufficient data are available for most targeted biogeographical regions.

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8

Wilson, Jeffrey A., and Paul C. Sereno. "Early Evolution and Higher-Level Phylogeny of Sauropod Dinosaurs." Memoir. Society of Vertebrate Paleontology 5 (June 15, 1998): 1. http://dx.doi.org/10.2307/3889325.

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9

Sereno, Paul. "Taxonomy, morphology, masticatory function and phylogeny of heterodontosaurid dinosaurs." ZooKeys 226 (October 3, 2012): 1–225. http://dx.doi.org/10.3897/zookeys.223.2840.

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Heterodontosaurids comprise an important early radiation of small-bodied herbivores that persisted for approximately 100 My from Late Triassic to Early Cretaceous time. Review of available fossils unequivocally establishes Echinodon as a very small-bodied, late-surviving northern heterodontosaurid similar to the other northern genera Fruitadens and Tianyulong. Tianyulong from northern China has unusual skeletal proportions, including a relatively large skull, short forelimb, and long manual digit II. The southern African heterodontosaurid genus Lycorhinus is established as valid, and a new taxon from the same formation is named Pegomastax africanusgen. n., sp. n. Tooth replacement and tooth-to-tooth wear is more common than previously thought among heterodontosaurids, and in Heterodontosaurus the angle of tooth-to-tooth shear is shown to increase markedly during maturation. Long-axis rotation of the lower jaw during occlusion is identified here as the most likely functional mechanism underlying marked tooth wear in mature specimens of Heterodontosaurus. Extensive tooth wear and other evidence suggests that all heterodontosaurids were predominantly or exclusively herbivores. Basal genera such as Echinodon, Fruitadens and Tianyulong with primitive, subtriangular crowns currently are known only from northern landmasses. All other genera except the enigmatic Pisanosaurus have deeper crown proportions and currently are known only from southern landmasses.

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Sereno, Paul. "Taxonomy, morphology, masticatory function and phylogeny of heterodontosaurid dinosaurs." ZooKeys 226 (October 3, 2012): 1–225. http://dx.doi.org/10.3897/zookeys.226.2840.

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11

Wilson, Jeffrey A., and Paul C. Sereno. "Early Evolution and Higher-Level Phylogeny of Sauropod Dinosaurs." Journal of Vertebrate Paleontology 18, sup002 (June 15, 1998): 1–79. http://dx.doi.org/10.1080/02724634.1998.10011115.

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12

Li, Yimeng, Marcello Ruta, and Matthew A. Wills. "Craniodental and Postcranial Characters of Non-Avian Dinosauria Often Imply Different Trees." Systematic Biology 69, no. 4 (November 26, 2019): 638–59. http://dx.doi.org/10.1093/sysbio/syz077.

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Abstract Despite the increasing importance of molecular sequence data, morphology still makes an important contribution to resolving the phylogeny of many groups, and is the only source of data for most fossils. Most systematists sample morphological characters as broadly as possible on the principle of total evidence. However, it is not uncommon for sampling to be focused on particular aspects of anatomy, either because characters therein are believed to be more informative, or because preservation biases restrict what is available. Empirically, the optimal trees from partitions of morphological data sets often represent significantly different hypotheses of relationships. Previous work on hard-part versus soft-part characters across animal phyla revealed significant differences in about a half of sampled studies. Similarly, studies of the craniodental versus postcranial characters of vertebrates revealed significantly different trees in about one-third of cases, with the highest rates observed in non-avian dinosaurs. We test whether this is a generality here with a much larger sample of 81 published data matrices across all major dinosaur groups. Using the incongruence length difference test and two variants of the incongruence relationship difference test, we found significant incongruence in about 50% of cases. Incongruence is not uniformly distributed across major dinosaur clades, being highest (63%) in Theropoda and lowest (25%) in Thyreophora. As in previous studies, our partition tests show some sensitivity to matrix dimensions and the amount and distribution of missing entries. Levels of homoplasy and retained synapomorphy are similar between partitions, such that incongruence must partly reflect differences in patterns of homoplasy between partitions, which may itself be a function of modularity and mosaic evolution. Finally, we implement new tests to determine which partition yields trees most similar to those from the entire matrix. Despite no bias across dinosaurs overall, there are striking differences between major groups. The craniodental characters of Ornithischia and the postcranial characters of Saurischia yield trees most similar to the “total evidence” trees derived from the entire matrix. Trees from these same character partitions also tend to be most stratigraphically congruent: a mutual consilience suggesting that those partitions yield more accurate trees. [Dinosauria; homoplasy; partition homogeneity.]

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13

Button, Khai, Hailu You, James I. Kirkland, and Lindsay Zanno. "Incremental growth of therizinosaurian dental tissues: implications for dietary transitions in Theropoda." PeerJ 5 (December 11, 2017): e4129. http://dx.doi.org/10.7717/peerj.4129.

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Previous investigations document functional and phylogenetic signals in the histology of dinosaur teeth. In particular, incremental lines in dentin have been used to determine tooth growth and replacement rates in several dinosaurian clades. However, to date, few studies have investigated the dental microstructure of theropods in the omnivory/herbivory spectrum. Here we examine dental histology of Therizinosauria, a clade of large-bodied theropods bearing significant morphological evidence for herbivory, by examining the teeth of the early-diverging therizinosaurian Falcarius utahensis, and an isolated tooth referred to Suzhousaurus megatherioides, a highly specialized large-bodied representative. Despite attaining some of the largest body masses among maniraptoran theropod dinosaurs, therizinosaurian teeth are diminutive, measuring no more than 0.90 cm in crown height (CH) and 0.38 cm in crown base length (CBL). Comparisons with other theropods and non-theropodan herbivorous dinosaurs reveals that when controlling for estimated body mass, crown volume in therizinosaurians plots most closely with dinosaurs of similar dietary strategy as opposed to phylogenetic heritage. Analysis of incremental growth lines in dentin, observed in thin sections of therizinosaurian teeth, demonstrates that tooth growth rates fall within the range of other archosaurs, conforming to hypothesized physiological limitations on the production of dental tissues. Despite dietary differences between therizinosaurians and hypercarnivorous theropods, the types of enamel crystallites present and their spatial distribution—i.e., the schmelzmuster of both taxa—is limited to parallel enamel crystallites, the simplest form of enamel and the plesiomorphic condition for Theropoda. This finding supports previous hypotheses that dental microstructure is strongly influenced by phylogeny, yet equally supports suggestions of reduced reliance on oral processing in omnivorous/herbivorous theropods rather than the microstructural specializations to diet exhibited by non-theropodan herbivorous dinosaurs. Finally, although our sample is limited, we document a significant reduction in the rate of enamel apposition contrasted with increased relative enamel thickness between early and later diverging therizinosaurians that coincides with anatomical evidence for increased specializations to herbivory in the clade.

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14

Mateus, Octávio, Susannah C. R. Maidment, and Nicolai A. Christiansen. "A new long-necked ‘sauropod-mimic’ stegosaur and the evolution of the plated dinosaurs." Proceedings of the Royal Society B: Biological Sciences 276, no. 1663 (February 25, 2009): 1815–21. http://dx.doi.org/10.1098/rspb.2008.1909.

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Stegosaurian dinosaurs have a quadrupedal stance, short forelimbs, short necks, and are generally considered to be low browsers. A new stegosaur, Miragaia longicollum gen. et sp. nov., from the Late Jurassic of Portugal, has a neck comprising at least 17 cervical vertebrae. This is eight additional cervical vertebrae when compared with the ancestral condition seen in basal ornithischians such as Scutellosaurus . Miragaia has a higher cervical count than most of the iconically long-necked sauropod dinosaurs. Long neck length has been achieved by ‘cervicalization’ of anterior dorsal vertebrae and probable lengthening of centra. All these anatomical features are evolutionarily convergent with those exhibited in the necks of sauropod dinosaurs. Miragaia longicollum is based upon a partial articulated skeleton, and includes the only known cranial remains from any European stegosaur. A well-resolved phylogeny supports a new clade that unites Miragaia and Dacentrurus as the sister group to Stegosaurus ; this new topology challenges the common view of Dacentrurus as a basal stegosaur.

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15

Rezende, Enrico L., Leonardo D. Bacigalupe, Roberto F. Nespolo, and Francisco Bozinovic. "Shrinking dinosaurs and the evolution of endothermy in birds." Science Advances 6, no. 1 (January 2020): eaaw4486. http://dx.doi.org/10.1126/sciadv.aaw4486.

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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.

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16

Birchard, Geoffrey F., Marcello Ruta, and D. Charles Deeming. "Evolution of parental incubation behaviour in dinosaurs cannot be inferred from clutch mass in birds." Biology Letters 9, no. 4 (August 23, 2013): 20130036. http://dx.doi.org/10.1098/rsbl.2013.0036.

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A recent study proposed that incubation behaviour (i.e. type of parental care) in theropod dinosaurs can be inferred from an allometric analysis of clutch volume in extant birds. However, the study in question failed to account for factors known to affect egg and clutch size in living bird species. A new scaling analysis of avian clutch mass demonstrates that type of parental care cannot be distinguished by conventional allometry because of the confounding effects of phylogeny and hatchling maturity. Precociality of young but not paternal care in the theropod ancestors of birds is consistent with the available data.

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17

Feduccia, Alan. "FANTASY VS REALITY: A Critique of Smith et al.'s Bird Origins." Open Ornithology Journal 9, no. 1 (April 30, 2016): 14–38. http://dx.doi.org/10.2174/1874453201609010014.

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Adherents of the current orthodoxy of a derivation of birds from theropod dinosaurs, criticize the commentary by Feduccia (2013, Auk, 130) [1 - 12] entitled “Bird Origins Anew” as well as numerous papers by Lingham-Soliar on theropod dermal fibers, using numerous mischaracterizations and misstatements of content, and illustrate their own misconceptions of the nature of the debate, which are here clarified. While there is general agreement with the affinity of birds and maniraptorans, the widely accepted phylogeny, advocating derived earth-bound maniraptorans giving rise to more primitive avians (i.e. Archaeopteryx), may be “topsy-turvy.” The current primary debate concerns whether maniraptorans are ancestral or derived within the phylogeny, and whether many maniraptorans and birds form a clade distinct from true theropods. Corollaries of the current scheme show largely terrestrial maniraptoran theropods similar to the Late CretaceousVelociraptorgiving rise to avians, and flight originatingviaa terrestrial (cursorial) “gravity-resisted,” as opposed to an arboreal “gravity-assisted” model. The current dogma posits pennaceous flight remiges in earth-bound theropods having evolved in terrestrial theropods that never flew. As part of the orthodoxy, fully feathered maniraptorans such as the tetrapteryx glidersMicroraptorand allies, are incorrectly reconstructed as terrestrial cursors, when in reality their anatomy and elongate hindlimb feathers would be a hindrance to terrestrial locomotion.The same is true of many early birds, exemplified by reconstruction of the arboreally adaptedConfuciusornisas a terrestrial predator, part of the overall theropodan scheme of birds evolving from terrestrial dinosaurs, and flight from the ground up. Both sides of this contentious debate must be constantly aware that new fossil or even molecular discoveries on birds may change current conclusions.

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18

Weishampel, David B. "The evolution of ornithischian dinosaurs during the Cretaceous: jaws, plants, and evolutionary metrics revisited." Paleontological Society Special Publications 6 (1992): 308. http://dx.doi.org/10.1017/s2475262200008686.

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Coevolutionary links between plants and herbivores, often cited as examples of adaptive response of one group of organisms to another, have been much studied from both neontological and paleontological perspectives. The most commonly cited case of coevolution from the latter viewpoint is the radiation of grassland grasses and grazing mammals during the mid-Tertiary. Other promising examples are also beginning to emerge, among them the radiation of ornithischian dinosaurs and early angiosperms during the Cretaceous.Preliminary studies (Weishampel and Norman 1989) analyzed the temporal distribution of trophic groups among Ornithischia (and other herbivorous tetrapods) across the Mesozoic. Trophic groups were based on a mixture of monophyletic and paraphyletic taxa assigned to assorted taxonomic rank. Speciation, extinction, and turn-over rates were calculated from stratigraphic data to identify co-evolutionary “hot spots” between herbivores and contemporary plants: times of evolutionary perturbation between these two groups of organisms within the Mesozoic.The present study reanalyzes Ornithischia from the perspective of ecosystem richness and phylogeny. As in the previous study, trophic categories are assessed on the basis of tooth morphology, occlusal patterns, and jaw construction. All ornithischians appear to orally process food in ways ranging from orthal pulping (ankylosaurs, most pachycephalosaurs) to orthal slicing and transverse grinding (euornithopodans, ceratopsians, some pachycephalosaurs).During the Early Cretaceous, relative species-level trophic diversity (as expressed as percentages) for ornithischians consists of a subequal mixture of herbivores with a transverse power-stroke (euornithopodans) and orthal pulpers (ankylosaurs, rare pachycephalosaurs). Toward the end of the Early Cretaceous, orthal slicing herbivores (ceratopsians) have their earliest record. At the end of the Cretaceous (Santonian-Maastrichtian), the transverse-chewing euornithopodans contribute somewhat less toward relative diversity, while the orthal slicing ceratopsians diversify and orthal pulpers decline (mostly due to reduced ankylosaur diversity).The pattern of acquisition of feeding/chewing styles among Cretaceous ornithischians is determined by mapping trophic categories on the phylogeny of the clade. With this in mind, our knowledge of the phylogeny of ornithischian tropic organization is in part a product of the completeness of the fossil record of these animals. Errors that may accrue because of a patchy record can be partially corrected by combining phylogenetic and stratigraphic information. This approach calls for the identification of ghost lineages, as well as their calibration using minimal divergence times (MDTs). Thus, diversity counts based on monophyly and evolutionary continuing can be augmented for yet-to-be-discovered species. Using ghost lineages and MDTs, a fuller picture of the pattern of acquisition of different jaw systems (and hence trophic organization) among ornithischian will become available.

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Tarver, J. E., P. C. J. Donoghue, and M. J. Benton. "Is evolutionary history repeatedly rewritten in light of new fossil discoveries?" Proceedings of the Royal Society B: Biological Sciences 278, no. 1705 (September 2010): 599–604. http://dx.doi.org/10.1098/rspb.2010.0663.

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Mass media and popular science journals commonly report that new fossil discoveries have ‘rewritten evolutionary history’. Is this merely journalistic hyperbole or is our sampling of systematic diversity so limited that attempts to derive evolutionary history from these datasets are premature? We use two exemplars—catarrhine primates (Old World monkeys and apes) and non-avian dinosaurs—to investigate how the maturity of datasets can be assessed. Both groups have been intensively studied over the past 200 years and so should represent pinnacles in our knowledge of vertebrate systematic diversity. We test the maturity of these datasets by assessing the completeness of their fossil records, their susceptibility to changes in macroevolutionary hypotheses and the balance of their phylogenies through study time. Catarrhines have shown prolonged stability, with discoveries of new species being evenly distributed across the phylogeny, and thus have had little impact on our understanding of their fossil record, diversification and evolution. The reverse is true for dinosaurs, where the addition of new species has been non-random and, consequentially, their fossil record, tree shape and our understanding of their diversification is rapidly changing. The conclusions derived from these analyses are relevant more generally: the maturity of systematic datasets can and should be assessed before they are exploited to derive grand macroevolutionary hypotheses.

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Bonnan, Matthew F. "The evolution of manus shape in sauropod dinosaurs: implications for functional morphology, forelimb orientation, and phylogeny." Journal of Vertebrate Paleontology 23, no. 3 (September 12, 2003): 595–613. http://dx.doi.org/10.1671/a1108.

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21

Brochu, Christopher A. "Progress and future directions in archosaur phylogenetics." Journal of Paleontology 75, no. 6 (November 2001): 1185–201. http://dx.doi.org/10.1017/s0022336000017236.

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The basic structure of archosaurian phylogeny is understood to include two primary crown-group lineages—one leading to living crocodiles and including a broad diversity of Triassic animals (e.g., phytosaurs, rauisuchians, aetosaurs), and another leading to dinosaurs (living and extinct). These lineages were established by the middle Triassic. A few extinct groups remain controversial, such as the pterosaurs, and debate persists over the phylogenetic relationships among extant bird lineages, which have proved difficult to resolve, and divergence timing estimates within Aves and Crocodylia remain the source of contention. A few analyses support a close relationship between archosaurs and turtles, or even a nesting of turtles within Archosauria. All sources of information used to resolve these issues have weaknesses, and these problems all involve highly derived lineages when they first appear in the fossil record.

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Sereno, Paul. "Corrigenda: Sereno PC (2012) Taxonomy, morphology, masticatory function and phylogeny of heterodontosaurid dinosaurs. ZooKeys 226: 1–225." ZooKeys 227 (October 9, 2012): 101. http://dx.doi.org/10.3897/zookeys.227.4091.

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23

Brusatte, Stephen L., Shaena Montanari, Hong-yu Yi, and Mark A. Norell. "Phylogenetic corrections for morphological disparity analysis: new methodology and case studies." Paleobiology 37, no. 1 (2011): 1–22. http://dx.doi.org/10.1666/09057.1.

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Taxonomic diversity and morphological disparity are different measures of biodiversity that together can describe large-scale evolutionary patterns. Diversity measures are often corrected by extending lineages back in time or adding additional taxa necessitated by a phylogeny, but disparity analyses focus on observed taxa only. This is problematic because some morphologies required by phylogeny are not included, some of which may help fill poorly sampled time bins. Moreover the taxic nature of disparity analyses makes it difficult to compare disparity measures with phylogenetically corrected diversity or morphological evolutionary rate curves. We present a general method for using phylogeny to correct measures of disparity, by including reconstructed ancestors in the disparity analysis. We apply this method to discrete character data sets focusing on Triassic archosaurs, Cenozoic carnivoramorph mammals, and Cretaceous-Cenozoic euarchontogliran mammals. Phylogenetic corrections do not simply mirror the taxic disparity patterns, but affect the three analyses in heterogeneous ways. Adding reconstructed ancestors can inflate morphospace, and the amount and direction of expansion differs depending on the taxonomic group in question. In some cases phylogenetic corrections give a temporal disparity curve indistinguishable from the taxic trend, but in other cases disparity is elevated in earlier time intervals relative to later bins, due to the extension of unsampled morphologies further back in time. The phylogenetic disparity curve for archosaurs differs little from the taxic curve, supporting a previously documented pattern of decoupled disparity and rates of morphological change in dinosaurs and their early contemporaries. Although phylogenetic corrections should not be used blindly, they are helpful when studying clades with major unsampled gaps in their fossil records.

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Mannion, Philip D., Paul Upchurch, Xingsheng Jin, and Wenjie Zheng. "New information on the Cretaceous sauropod dinosaurs of Zhejiang Province, China: impact on Laurasian titanosauriform phylogeny and biogeography." Royal Society Open Science 6, no. 8 (August 2019): 191057. http://dx.doi.org/10.1098/rsos.191057.

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Titanosaurs were a globally distributed clade of Cretaceous sauropods. Historically regarded as a primarily Gondwanan radiation, there is a growing number of Eurasian taxa, with several putative titanosaurs contemporaneous with, or even pre-dating, the oldest known Southern Hemisphere remains. The early Late Cretaceous Jinhua Formation, in Zhejiang Province, China, has yielded two putative titanosaurs, Jiangshanosaurus lixianensis and Dongyangosaurus sinensis . Here, we provide a detailed re-description and diagnosis of Jiangshanosaurus , as well as new anatomical information on Dongyangosaurus . Previously, a ‘derived’ titanosaurian placement for Jiangshanosaurus was primarily based on the presence of procoelous anterior caudal centra. We show that this taxon had amphicoelous anterior-middle caudal centra. Its only titanosaurian synapomorphy is that the dorsal margins of the scapula and coracoid are approximately level with one another. Dongyangosaurus can clearly be differentiated from Jiangshanosaurus , and displays features that indicate a closer relationship to the titanosaur radiation. Revised scores for both taxa are incorporated into an expanded phylogenetic data matrix, comprising 124 taxa scored for 548 characters. Under equal weights parsimony, Jiangshanosaurus is recovered as a member of the non-titanosaurian East Asian somphospondylan clade Euhelopodidae, and Dongyangosaurus lies just outside of Titanosauria. However, when extended implied weighting is applied, both taxa are placed within Titanosauria. Most other ‘middle’ Cretaceous East Asian sauropods are probably non-titanosaurian somphospondylans, but at least Xianshanosaurus appears to belong to the titanosaur radiation. Our analyses also recover the Early Cretaceous European sauropod Normanniasaurus genceyi as a ‘derived’ titanosaur, clustering with Gondwanan taxa. These results provide further support for a widespread diversification of titanosaurs by at least the Early Cretaceous.

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Foth, Christian, Brandon P. Hedrick, and Martin D. Ezcurra. "Cranial ontogenetic variation in early saurischians and the role of heterochrony in the diversification of predatory dinosaurs." PeerJ 4 (January 18, 2016): e1589. http://dx.doi.org/10.7717/peerj.1589.

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Non-avian saurischian skulls underwent at least 165 million years of evolution and shapes varied from elongated skulls, such as in the theropodCoelophysis, to short and box-shaped skulls, such as in the sauropodCamarasaurus. A number of factors have long been considered to drive skull shape, including phylogeny, dietary preferences and functional constraints. However, heterochrony is increasingly being recognized as an important factor in dinosaur evolution. In order to quantitatively analyse the impact of heterochrony on saurischian skull shape, we analysed five ontogenetic trajectories using two-dimensional geometric morphometrics in a phylogenetic framework. This allowed for the comparative investigation of main ontogenetic shape changes and the evaluation of how heterochrony affected skull shape through both ontogenetic and phylogenetic trajectories. Using principal component analyses and multivariate regressions, it was possible to quantify different ontogenetic trajectories and evaluate them for evidence of heterochronic events allowing testing of previous hypotheses on cranial heterochrony in saurischians. We found that the skull shape of the hypothetical ancestor of Saurischia likely led to basal Sauropodomorpha through paedomorphosis, and to basal Theropoda mainly through peramorphosis. Paedomorphosis then led from Orionides to Avetheropoda, indicating that the paedomorphic trend found by previous authors in advanced coelurosaurs may extend back into the early evolution of Avetheropoda. Not only are changes in saurischian skull shape complex due to the large number of factors that affected it, but heterochrony itself is complex, with a number of possible reversals throughout non-avian saurischian evolution. In general, the sampling of complete ontogenetic trajectories including early juveniles is considerably lower than the sampling of single adult or subadult individuals, which is a major impediment to the study of heterochrony on non-avian dinosaurs. Thus, the current work represents an exploratory analysis. To better understand the cranial ontogeny and the impact of heterochrony on skull evolution in saurischians, the data set that we present here must be expanded and complemented with further sampling from future fossil discoveries, especially of juvenile individuals.

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França, Marco A. G., Júlio C. de A. Marsola, Douglas Riff, Annie S. Hsiou, and Max C. Langer. "New lower jaw and teeth referred toMaxakalisaurus topai(Titanosauria: Aeolosaurini) and their implications for the phylogeny of titanosaurid sauropods." PeerJ 4 (June 8, 2016): e2054. http://dx.doi.org/10.7717/peerj.2054.

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Sauropod dinosaurs compose a diversified, well known, and worldwide distributed clade, with a stereotyped body plan: deep trunk, elongated neck and tail, columnar limbs and very small skull. In Brazil, the group is represented by ten formally described Cretaceous species, mostly titanosaurs. This is the case ofMaxakalisaurus topai, known based on an incomplete and disarticulated skeleton, unearthed from deposits of the Adamantina Formation in Minas Gerais. Here, we report a partial right dentary, including five isolated teeth, collected from the same site as the type-series ofM. topaiand tentatively referred to that taxon. The bone is gently curved medially, the functional teeth are set on an anterolingual position, and two replacement teeth are seen per alveoli. New morphological data gathered from that specimen was employed to conduct a comprehensive phylogenetic analysis of Titanosauria (with 42 taxa and 253 characters), based on previous studies. The Aeolosaurini clade was recovered, withGondwanatitanandAelosaurusas sister taxa, andMaxakalisaurus,Panamericansaurus, andRinconsaurusforming a basal polytomy.

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MÜLLER, RODRIGO TEMP, MAX CARDOSO LANGER, and SÉRGIO DIAS-DA-SILVA. "Ingroup relationships of Lagerpetidae (Avemetatarsalia: Dinosauromorpha): a further phylogenetic investigation on the understanding of dinosaur relatives." Zootaxa 4392, no. 1 (March 7, 2018): 149. http://dx.doi.org/10.11646/zootaxa.4392.1.7.

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Despite representing a key-taxon in dinosauromorph phylogeny, Lagerpertidae is one of the most obscure and enigmatic branches from the stem that leads to the dinosaurs. Recent new findings have greatly increased our knowledge about lagerpetids, but no phylogenetic analysis has so far included all known members of this group. Here, we present the most inclusive phylogenetic study so far conducted for Lagerpetidae. Phylogenetic analyses were performed based on three independent data matrixes. In two of them, Lagerpeton chanarensis Romer, 1971 is the sister taxon to all other known Lagerpetidae, whereas Ixalerpeton polesinensis Cabreira et al., 2016 is in a sister group relationship with a clade that includes PVSJ 883 and Dromomeron. Conversely, the other analysis supports an alternative topology, where I. polesinensis is the sister taxon to either L. chanarensis or all other Lagerpetidae. Although coeval and geographically close, I. polesinensis and PVSJ 883 do not form a clade exclusive of other lagerpetids. As previously suggested D. gigas Martínez, Apaldetti, Correa & Abelín, 2016 is the sister taxon of D. romeri Irmis et al., 2007. The phylogenetic analyses also indicate that the earliest lagerpetids are restricted to southwestern Pangea, whereas later forms spread across the entire western portion of the supercontinent. Finally, quantification of the codified characters of our analysis reveals that Lagerpetidae is one of the poorest known among the Triassic dinosauromorph groups in terms of their anatomy, so that new discoveries of more complete specimens are awaited to establish a more robust phylogeny.

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HÜBNER, TOM R., and OLIVER W. M. RAUHUT. "A juvenile skull of Dysalotosaurus lettowvorbecki (Ornithischia: Iguanodontia), and implications for cranial ontogeny, phylogeny, and taxonomy in ornithopod dinosaurs." Zoological Journal of the Linnean Society 160, no. 2 (August 16, 2010): 366–96. http://dx.doi.org/10.1111/j.1096-3642.2010.00620.x.

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Stefanic, Candice M., and Sterling J. Nesbitt. "The evolution and role of the hyposphene-hypantrum articulation in Archosauria: phylogeny, size and/or mechanics?" Royal Society Open Science 6, no. 10 (October 2019): 190258. http://dx.doi.org/10.1098/rsos.190258.

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Living members of Archosauria, the reptile clade containing Crocodylia and Aves, have a wide range of skeletal morphologies, ecologies and body size. The range of body size greatly increases when extinct archosaurs are included, because extinct Archosauria includes the largest members of any terrestrial vertebrate group (e.g. 70-tonne titanosaurs, 20-tonne theropods). Archosaurs evolved various skeletal adaptations for large body size, but these adaptations varied among clades and did not always appear consistently with body size or ecology. Modification of intervertebral articulations, specifically the presence of a hyposphene-hypantrum articulation between trunk vertebrae, occurs in a variety of extinct archosaurs (e.g. non-avian dinosaurs, pseudosuchians). We surveyed the phylogenetic distribution of the hyposphene-hypantrum to test its relationship with body size. We found convergent evolution among large-bodied clades, except when the clade evolved an alternative mechanism for vertebral bracing. For example, some extinct lineages that lack the hyposphene-hypantrum articulation (e.g. ornithischians) have ossified tendons that braced their vertebral column. Ossified tendons are present even in small taxa and in small-bodied juveniles, but large-bodied taxa with ossified tendons reached those body sizes without evolving the hyposphene-hypantrum articulation. The hyposphene-hypantrum was permanently lost in extinct crownward members of both major archosaur lineages (i.e. Crocodylia and Aves) as they underwent phyletic size decrease, changes in vertebral morphology and shifts in ecology.

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Snively, Eric, Haley O’Brien, Donald M. Henderson, Heinrich Mallison, Lara A. Surring, Michael E. Burns, Thomas R. Holtz, et al. "Lower rotational inertia and larger leg muscles indicate more rapid turns in tyrannosaurids than in other large theropods." PeerJ 7 (February 21, 2019): e6432. http://dx.doi.org/10.7717/peerj.6432.

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Synopsis Tyrannosaurid dinosaurs had large preserved leg muscle attachments and low rotational inertia relative to their body mass, indicating that they could turn more quickly than other large theropods. Methods To compare turning capability in theropods, we regressed agility estimates against body mass, incorporating superellipse-based modeled mass, centers of mass, and rotational inertia (mass moment of inertia). Muscle force relative to body mass is a direct correlate of agility in humans, and torque gives potential angular acceleration. Agility scores therefore include rotational inertia values divided by proxies for (1) muscle force (ilium area and estimates of m. caudofemoralis longus cross-section), and (2) musculoskeletal torque. Phylogenetic ANCOVA (phylANCOVA) allow assessment of differences in agility between tyrannosaurids and non-tyrannosaurid theropods (accounting for both ontogeny and phylogeny). We applied conditional error probabilities a(p) to stringently test the null hypothesis of equal agility. Results Tyrannosaurids consistently have agility index magnitudes twice those of allosauroids and some other theropods of equivalent mass, turning the body with both legs planted or pivoting over a stance leg. PhylANCOVA demonstrates definitively greater agilities in tyrannosaurids, and phylogeny explains nearly all covariance. Mass property results are consistent with those of other studies based on skeletal mounts, and between different figure-based methods (our main mathematical slicing procedures, lofted 3D computer models, and simplified graphical double integration). Implications The capacity for relatively rapid turns in tyrannosaurids is ecologically intriguing in light of their monopolization of large (>400 kg), toothed dinosaurian predator niches in their habitats.

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Evers, Serjoscha W., Christian Foth, and Oliver W. M. Rauhut. "Notes on the cheek region of the Late Jurassic theropod dinosaur Allosaurus." PeerJ 8 (February 7, 2020): e8493. http://dx.doi.org/10.7717/peerj.8493.

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Allosaurus, from the Late Jurassic of North America and Europe, is a model taxon for Jurassic basal tetanuran theropod dinosaurs. It has achieved an almost iconic status due to its early discovery in the late, 19th century, and due to the abundance of material from the Morrison Formation of the western U.S.A., making Allosaurus one of the best-known theropod taxa. Despite this, various aspects of the cranial anatomy of Allosaurus are surprisingly poorly understood. Here, we discuss the osteology of the cheek region, comprised by the jugal, maxilla, and lacrimal. This region of the skull is of importance for Allosaurus taxonomy and phylogeny, particularly because Allosaurus has traditionally been reconstructed with an unusual cheek configuration, and because the European species Allosaurus europaeus has been said to be different from North American material in the configuration of these bones. Based on re-examination of articulated and disarticulated material from a number of repositories, we show that the jugal participates in the antorbital fenestra, contradicting the common interpretation. The jugal laterally overlies the lacrimal, and forms an extended antorbital fossa with this bone. Furthermore, we document previously unrecorded pneumatic features of the jugal of Allosaurus.

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Schmerge, Joshua D., and Bruce M. Rothschild. "Distribution of the dentary groove of theropod dinosaurs: Implications for theropod phylogeny and the validity of the genus Nanotyrannus Bakker et al., 1988." Cretaceous Research 61 (June 2016): 26–33. http://dx.doi.org/10.1016/j.cretres.2015.12.016.

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Wilkinson, Mark, Paul Upchurch, Paul M. Barrett, David J. Gower, and Michael J. Benton. "Robust dinosaur phylogeny?" Nature 396, no. 6710 (December 1998): 423–24. http://dx.doi.org/10.1038/24763.

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Brusatte, Stephen L., Thomas D. Carr, Thomas E. Williamson, Thomas R. Holtz, David W. E. Hone, and Scott A. Williams. "Dentary groove morphology does not distinguish ‘Nanotyrannus’ as a valid taxon of tyrannosauroid dinosaur. Comment on: “Distribution of the dentary groove of theropod dinosaurs: Implications for theropod phylogeny and the validity of the genus Nanotyrannus Bakker et al., 1988”." Cretaceous Research 65 (October 2016): 232–37. http://dx.doi.org/10.1016/j.cretres.2016.02.007.

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WILSON, JEFFREY A. "Sauropod dinosaur phylogeny: critique and cladistic analysis." Zoological Journal of the Linnean Society 136, no. 2 (September 13, 2002): 215–75. http://dx.doi.org/10.1046/j.1096-3642.2002.00029.x.

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Carrano, Matthew T., and Scott D. Sampson. "The Phylogeny of Ceratosauria (Dinosauria: Theropoda)." Journal of Systematic Palaeontology 6, no. 2 (January 1, 2008): 183–236. http://dx.doi.org/10.1017/s1477201907002246.

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Carrano, Matthew T., Roger B. J. Benson, and Scott D. Sampson. "The phylogeny of Tetanurae (Dinosauria: Theropoda)." Journal of Systematic Palaeontology 10, no. 2 (May 17, 2012): 211–300. http://dx.doi.org/10.1080/14772019.2011.630927.

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Carrano, Matthew T., Roger B. J. Benson, and Scott D. Sampson. "The phylogeny of Tetanurae (Dinosauria: Theropoda)." Journal of Systematic Palaeontology 10, no. 3 (September 2012): 599. http://dx.doi.org/10.1080/14772019.2012.713753.

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Maidment, Susannah C. R., David B. Norman, Paul M. Barrett, and Paul Upchurch. "Systematics and phylogeny of Stegosauria (Dinosauria: Ornithischia)." Journal of Systematic Palaeontology 6, no. 4 (January 2008): 367–407. http://dx.doi.org/10.1017/s1477201908002459.

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Raven, Thomas J., and Susannah C. R. Maidment. "A new phylogeny of Stegosauria (Dinosauria, Ornithischia)." Palaeontology 60, no. 3 (April 18, 2017): 401–8. http://dx.doi.org/10.1111/pala.12291.

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JI, QIANG, MARK A. NORELL, PETER J. MAKOVICKY, KE-QIN GAO, SHU'AN JI, and CHONGXI YUAN. "An Early Ostrich Dinosaur and Implications for Ornithomimosaur Phylogeny." American Museum Novitates 3420, no. 1 (2003): 1. http://dx.doi.org/10.1206/0003-0082(2003)420<0001:aeodai>2.0.co;2.

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McDonald, Andrew T. "Phylogeny of Basal Iguanodonts (Dinosauria: Ornithischia): An Update." PLoS ONE 7, no. 5 (May 22, 2012): e36745. http://dx.doi.org/10.1371/journal.pone.0036745.

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Brusatte, Stephen L., and Paul C. Sereno. "Phylogeny of Allosauroidea (Dinosauria: Theropoda): Comparative analysis and resolution." Journal of Systematic Palaeontology 6, no. 2 (January 1, 2008): 155–82. http://dx.doi.org/10.1017/s1477201907002404.

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Ezcurra, Martin D. "A new early dinosaur (Saurischia: Sauropodomorpha) from the Late Triassic of Argentina: a reassessment of dinosaur origin and phylogeny." Journal of Systematic Palaeontology 8, no. 3 (July 30, 2010): 371–425. http://dx.doi.org/10.1080/14772019.2010.484650.

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PRIETO-MÁRQUEZ, ALBERT. "Global phylogeny of Hadrosauridae (Dinosauria: Ornithopoda) using parsimony and Bayesian methods." Zoological Journal of the Linnean Society 159, no. 2 (May 26, 2010): 435–502. http://dx.doi.org/10.1111/j.1096-3642.2009.00617.x.

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Schmerge, J. D., and B. M. Rothschild. "When a groove is not a groove: Clarification of the appearance of the dentary groove in tyrannosauroid theropods and the distinction between Nanotyrannus and Tyrannosaurus. Reply to Comment on: “Distribution of the dentary groove of theropod dinosaurs: implications for theropod phylogeny and the validity of the genus Nanotyrannus Bakker et al., 1988”." Cretaceous Research 65 (October 2016): 238–43. http://dx.doi.org/10.1016/j.cretres.2016.04.015.

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Weishampel, David B., Coralia‐Maria Jianu, Zoltan Csiki, and David B. Norman. "Osteology and phylogeny ofZalmoxes(n. g.), an unusual Euornithopod dinosaur from the latest Cretaceous of Romania." Journal of Systematic Palaeontology 1, no. 2 (January 2003): 65–123. http://dx.doi.org/10.1017/s1477201903001032.

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Longrich, Nicholas. "Systematics of Chasmosaurus - new information from the Peabody Museum skull, and the use of phylogenetic analysis for dinosaur alpha taxonomy." F1000Research 4 (December 17, 2015): 1468. http://dx.doi.org/10.12688/f1000research.7573.1.

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The horned dinosaur Chasmosaurus from the late Campanian Dinosaur Park Formation of Alberta, is known from numerous skulls and skeletons, but over a century after its description, the taxonomy of the genus is controversial. Two species, Chasmosaurus belli and C. russelli, are currently recognized, with a third species, C. irvinensis, recently placed in a new genus, Vagaceratops. Here, the Yale Chasmosaurus skull is described, and implications for Chasmosaurus systematics are explored. The Yale skull is intermediate between typical C. belli and C. irvinensis. C. belli-like features include large, triangular lateral epiparietals, large parietal fenestrae, and an emarginate parietal. Yet the skull also exhibits derived features of C. irvinensis, including a posteriorly inclined narial strut, brow horns replaced by rugose bosses, reduced parietal emargination, five pairs of epiparietals, and epiparietals that fuse at their bases and hook forward over the frill. Specimen-level phylogenetic analysis provides a hypothesis of relationships upon which to base the taxonomy of Chasmosaurus. C. belli is paraphyletic with respect to C. irvinensis, and the Peabody skull is closer to C. irvinensis than to other C. belli. The holotype of C. russelli clusters with C. belli, making C. russelli a junior synonym of C. belli. Accordingly, Chasmosaurus can be divided into three species: C. belli, C. irvinensis, and C. priscus sp. nov, including specimens previously referred to C. russelli. The systematics of Chasmosaurus show how specimen level phylogeny can provide an evolutionary framework upon which to establish taxonomies. However, the resulting phylogenies may lead to paraphyletic species and genera.

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Wick, Steven L., and Thomas M. Lehman. "A new ceratopsian dinosaur from the Javelina Formation (Maastrichtian) of West Texas and implications for chasmosaurine phylogeny." Naturwissenschaften 100, no. 7 (June 1, 2013): 667–82. http://dx.doi.org/10.1007/s00114-013-1063-0.

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BRUSATTE, STEPHEN L., ROGER B. J. BENSON, PHILIP J. CURRIE, and ZHAO XIJIN. "The skull of Monolophosaurus jiangi (Dinosauria: Theropoda) and its implications for early theropod phylogeny and evolution." Zoological Journal of the Linnean Society 158, no. 3 (January 18, 2010): 573–607. http://dx.doi.org/10.1111/j.1096-3642.2009.00563.x.

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