scholarly journals The evolutionary history of polycotylid plesiosaurians

2018 ◽  
Vol 5 (3) ◽  
pp. 172177 ◽  
Author(s):  
V. Fischer ◽  
R. B. J. Benson ◽  
P. S. Druckenmiller ◽  
H. F. Ketchum ◽  
N. Bardet
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Phylogenetic Relationships ◽  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Neck Length ◽  
Ecological Release ◽  
Holotype Specimen ◽  
Low Diversity ◽  
History Of

Polycotylidae is a clade of plesiosaurians that appeared during the Early Cretaceous and became speciose and abundant early in the Late Cretaceous. However, this radiation is poorly understood. Thililua longicollis from the Middle Turonian of Morocco is an enigmatic taxon possessing an atypically long neck and, as originally reported, a series of unusual cranial features that cause unstable phylogenetic relationships for polycotylids. We reinterpret the holotype specimen of Thililua longicollis and clarify its cranial anatomy. Thililua longicollis possesses an extensive, foramina-bearing jugal, a premaxilla–parietal contact and carinated teeth. Phylogenetic analyses of a new cladistic dataset based on first-hand observation of most polycotylids recover Thililua and Mauriciosaurus as successive lineages at the base of the earliest Late Cretaceous polycotyline radiation. A new dataset summarizing the Bauplan of polycotylids reveals that their radiation produced an early burst of disparity during the Cenomanian–Turonian interval, with marked plasticity in relative neck length, but this did not arise as an ecological release following the extinction of ichthyosaurs and pliosaurids. This disparity vanished during and after the Turonian, which is consistent with a model of ‘early experimentation/late constraint’. Two polycotylid clades, Occultonectia clade nov. and Polycotylinae, survived up to the Maastrichtian, but with low diversity.

scholarly journals Diversification patterns based on the largest morphological phylogenetic analysis of Pleurodira

2015 ◽  
Author(s):  
Gabriel S Ferreira ◽  
Juliana Sterli ◽  
Mario Bronzati Filho ◽  
Max C Langer
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Evolutionary History ◽  
Feeding Habits ◽  
Phylogenetic Analyses ◽  
Morphological Data ◽  
Phylogenetic Hypothesis ◽  
Consensus Tree ◽  
Strict Consensus Tree ◽  
History Of

Background. Most studies on pleurodiran turtles are about the behavior and/or feeding habits analyzes, description of new taxa or specimens (both extinct and extant), or phylogenetic analyzes of one of its subclades with extant taxa: Chelidae, Pelomedusidae or Podocnemididae. With the exception of some molecular phylogenies, there are no phylogenetic analyses of extant and extinct representatives of Pleurodira including all of its lineages. A broader understanding of the evolutionary history of Pleurodira requires a phylogenetic hypothesis based on more extensive taxonomic and character samplings.Methods. We constructed a taxon-character matrix including 227 morphological characters and 87 taxa from all the Pleurodira lineages, plus one stem Pan-Pleurodira, Notoemys laticentralis, and one stem-Testudinata, Proganochelys quenstedti, as outgroups. The resulting matrix was analyzed using parsimony, Tree Bisection and Reconnection (TBR) algorithms, with 5000 replicates, and a hold of 20. The obtained strict consensus tree was used as the basis of a diversification analysis using topology-based methods. A nestedgrowing tree approach was employed to create a corresponding tree for different intervals of the geological history of the group. Six distinct time bins were created for periods in which members of Pleurodira occur: Early Cretaceous, Late Cretaceous, Paleocene, Eocene, Miocene, and Recent. Results. All main pleurodiran clades were recovered in the strict consensus tree, but with some changes in their relationship compared to previous analyses, e.g. the inclusiveness of both Pelomedusoides and Bothremydidae. The diversification analysis shows that, after the establishment of the two major lineages (i.e. Chelidae and Pelomedusoides) in the Early Cretaceous, these subgroups diversified in distinct rates along their evolutionary history. Two main diversification shifts were identified: one at the early evolution of Podocnemoidea, during the Late Cretaceous, and another during the Miocene, deep nested in the Podocnemididae clade. Discussion. The resulting strict consensus tree is the largest exclusive phylogenetic hypothesis for Pleurodira, including both extant and extinct taxa. Based on morphological data, it allows more inclusive inferences on the general morphological and diversification patterns of the group. The diversification pulses analysis suggests variation on the rates of diversification on the different pleurodiran clades. The first shift detected is related to the great radiation of Bothremydidae and Podocnemoidae in the Late Cretaceous; the second shift, detected in the Miocene, is related to a diversification within the Stereogenyina, a Podocnemididae clade. Ongoing analysis will determine which factors could enforce those different diversification rates in the evolution of Pleurodira.

scholarly journals Diversification patterns based on the largest morphological phylogenetic analysis of Pleurodira

2015 ◽  
Author(s):  
Gabriel S Ferreira ◽  
Juliana Sterli ◽  
Mario Bronzati Filho ◽  
Max C Langer
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Evolutionary History ◽  
Feeding Habits ◽  
Phylogenetic Analyses ◽  
Morphological Data ◽  
Phylogenetic Hypothesis ◽  
Consensus Tree ◽  
Strict Consensus Tree ◽  
History Of

Background. Most studies on pleurodiran turtles are about the behavior and/or feeding habits analyzes, description of new taxa or specimens (both extinct and extant), or phylogenetic analyzes of one of its subclades with extant taxa: Chelidae, Pelomedusidae or Podocnemididae. With the exception of some molecular phylogenies, there are no phylogenetic analyses of extant and extinct representatives of Pleurodira including all of its lineages. A broader understanding of the evolutionary history of Pleurodira requires a phylogenetic hypothesis based on more extensive taxonomic and character samplings.Methods. We constructed a taxon-character matrix including 227 morphological characters and 87 taxa from all the Pleurodira lineages, plus one stem Pan-Pleurodira, Notoemys laticentralis, and one stem-Testudinata, Proganochelys quenstedti, as outgroups. The resulting matrix was analyzed using parsimony, Tree Bisection and Reconnection (TBR) algorithms, with 5000 replicates, and a hold of 20. The obtained strict consensus tree was used as the basis of a diversification analysis using topology-based methods. A nestedgrowing tree approach was employed to create a corresponding tree for different intervals of the geological history of the group. Six distinct time bins were created for periods in which members of Pleurodira occur: Early Cretaceous, Late Cretaceous, Paleocene, Eocene, Miocene, and Recent. Results. All main pleurodiran clades were recovered in the strict consensus tree, but with some changes in their relationship compared to previous analyses, e.g. the inclusiveness of both Pelomedusoides and Bothremydidae. The diversification analysis shows that, after the establishment of the two major lineages (i.e. Chelidae and Pelomedusoides) in the Early Cretaceous, these subgroups diversified in distinct rates along their evolutionary history. Two main diversification shifts were identified: one at the early evolution of Podocnemoidea, during the Late Cretaceous, and another during the Miocene, deep nested in the Podocnemididae clade. Discussion. The resulting strict consensus tree is the largest exclusive phylogenetic hypothesis for Pleurodira, including both extant and extinct taxa. Based on morphological data, it allows more inclusive inferences on the general morphological and diversification patterns of the group. The diversification pulses analysis suggests variation on the rates of diversification on the different pleurodiran clades. The first shift detected is related to the great radiation of Bothremydidae and Podocnemoidae in the Late Cretaceous; the second shift, detected in the Miocene, is related to a diversification within the Stereogenyina, a Podocnemididae clade. Ongoing analysis will determine which factors could enforce those different diversification rates in the evolution of Pleurodira.

scholarly journals Integrated phylogenomic and fossil evidence of stick and leaf insects (Phasmatodea) reveal a Permian–Triassic co-origination with insectivores

2020 ◽  
Vol 7 (11) ◽  
pp. 201689
Author(s):  
Erik Tihelka ◽  
Chenyang Cai ◽  
Mattia Giacomelli ◽  
Davide Pisani ◽  
Philip C. J. Donoghue
Keyword(s):  
Late Cretaceous ◽  
Molecular Clock ◽  
Phylogenetic Relationships ◽  
Evolutionary History ◽  
Plant Tissues ◽  
Transcriptomic Data ◽  
Insect Order ◽  
Fossil Evidence ◽  
History Of ◽  
Cretaceous Terrestrial Revolution

Stick and leaf insects (Phasmatodea) are a distinctive insect order whose members are characterized by mimicking various plant tissues such as twigs, foliage and bark. Unfortunately, the phylogenetic relationships among phasmatodean subfamilies and the timescale of their evolution remain uncertain. Recent molecular clock analyses have suggested a Cretaceous–Palaeogene origin of crown Phasmatodea and a subsequent Cenozoic radiation, contrasting with fossil evidence. Here, we analysed transcriptomic data from a broad diversity of phasmatodeans and, combined with the assembly of a new suite of fossil calibrations, we elucidate the evolutionary history of stick and leaf insects. Our results differ from recent studies in the position of the leaf insects (Phylliinae), which are recovered as sister to a clade comprising Clitumninae, Lancerocercata, Lonchodinae, Necrosciinae and Xenophasmina . We recover a Permian to Triassic origin of crown Phasmatodea coinciding with the radiation of early insectivorous parareptiles, amphibians and synapsids. Aschiphasmatinae and Neophasmatodea diverged in the Jurassic–Early Cretaceous. A second spur in origination occurred in the Late Cretaceous, coinciding with the Cretaceous Terrestrial Revolution, and was probably driven by visual predators such as stem birds (Enantiornithes) and the radiation of angiosperms.

Phylogenetic relationships among Elymus and related diploid genera (Triticeae: Poaceae) based on nuclear rDNA ITS sequences

Biologia ◽  
2015 ◽  
Vol 70 (2) ◽  
Author(s):  
Gang Gao ◽  
Jia-bin Deng ◽  
Xue-mei Gou ◽  
Qian Wang ◽  
Chun-bang Ding ◽  
...  
Keyword(s):  
Phylogenetic Relationships ◽  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Its Sequences ◽  
Neighbor Joining ◽  
Rdna Its ◽  
Genome Donor ◽  
Rdna Its Sequences ◽  
History Of ◽  
Elymus Species

AbstractTo investigate the phylogenetic relationships among Elymus and related diploid genera, the genome donor of Elymus, and the evolutionary history of polyploid Elymus species, nuclear ribosomal internal transcribed spacer (ITS) sequences were analyzed for 10 Elymus species, together with 17 diploid taxa from 5 monogenomic genera. The phylogenetic analyses (Neighbor-Joining) supported two major clades (St and H). Sequence diversity and genealogical analysis suggested that (1) Elymus species were unambiguously closely related to Pseudoroegeria; (2) Pse. stipifolia might be serve as the St genome donor of polyploid Elymus species; (3) the Y genome might be originated from ancestral lineage of Pseudoroegneria (St); (4) the ITS sequences of Elymus were evolutionarily distinct and may clarify parental lineages and phylogenetic relationships in Elymus.

scholarly journals A basal thunnosaurian from Iraq reveals disparate phylogenetic origins for Cretaceous ichthyosaurs

2013 ◽  
Vol 9 (4) ◽  
pp. 20130021 ◽  
Author(s):  
Valentin Fischer ◽  
Robert M. Appleby ◽  
Darren Naish ◽  
Jeff Liston ◽  
James B. Riding ◽  
...  
Keyword(s):  
Middle East ◽  
Early Cretaceous ◽  
Late Jurassic ◽  
Evolutionary History ◽  
Early Jurassic ◽  
Late Triassic ◽  
Low Diversity ◽  
History Of

Cretaceous ichthyosaurs have typically been considered a small, homogeneous assemblage sharing a common Late Jurassic ancestor. Their low diversity and disparity have been interpreted as indicative of a decline leading to their Cenomanian extinction. We describe the first post-Triassic ichthyosaur from the Middle East, Malawania anachronus gen. et sp. nov. from the Early Cretaceous of Iraq, and re-evaluate the evolutionary history of parvipelvian ichthyosaurs via phylogenetic and cladogenesis rate analyses. Malawania represents a basal grade in thunnosaurian evolution that arose during a major Late Triassic radiation event and was previously thought to have gone extinct during the Early Jurassic. Its pectoral morphology appears surprisingly archaic, retaining a forefin architecture similar to that of its Early Jurassic relatives. After the initial latest Triassic radiation of early thunnosaurians, two subsequent large radiations produced lineages with Cretaceous representatives, but the radiation events themselves are pre-Cretaceous. Cretaceous ichthyosaurs therefore include distantly related lineages, with contrasting evolutionary histories, and appear more diverse and disparate than previously supposed.

scholarly journals Intrahost speciations and host switches shaped the evolution of herpesviruses

2018 ◽  
Author(s):  
Anderson F. Brito ◽  
John W. Pinney
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Continental Drift ◽  
Divergence Times ◽  
Crucial Information ◽  
Host Evolution ◽  
Over Time

ABSTRACTCospeciation has been suggested to be the main force driving the evolution of herpesviruses, with viral species co-diverging with their hosts along more than 400 million years of evolutionary history. Recent studies, however, have been challenging this assumption, showing that other co-phylogenetic events, such as intrahost speciations and host switches play a central role on their evolution. Most of these studies, however, were performed with undated phylogenies, which may underestimate or overestimate the frequency of certain events. In this study we performed co-phylogenetic analyses using time-calibrated trees of herpesviruses and their hosts. This approach allowed us to (i) infer co-phylogenetic events over time, and (ii) integrate crucial information about continental drift and host biogeography to better understand virus-host evolution. We observed that cospeciations were in fact relatively rare events, taking place mostly after the Late Cretaceous (~100 Millions of years ago). Host switches were particularly common among alphaherpesviruses, where at least 10 transfers were detected. Among beta- and gammaherpesviruses, transfers were less frequent, with intrahost speciations followed by losses playing more prominent roles, especially from the Early Jurassic to the Early Cretaceous, when those viral lineages underwent several intrahost speciations. Our study reinforces the understanding that cospeciations are uncommon events in herpesvirus evolution. More than topological incongruences, mismatches in divergence times were the main disagreements between host and viral phylogenies. In most cases, host switches could not explain such disparities, highlighting the important role of losses and intrahost speciations in the evolution of herpesviruses.

scholarly journals An unusual bird (Theropoda, Avialae) from the Early Cretaceous of Japan suggests complex evolutionary history of basal birds

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Takuya Imai ◽  
Yoichi Azuma ◽  
Soichiro Kawabe ◽  
Masateru Shibata ◽  
Kazunori Miyata ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Eastern China ◽  
First Record ◽  
New Taxon ◽  
Jehol Biota ◽  
North Eastern ◽  
History Of ◽  
Complex Evolutionary History

AbstractThe Early Cretaceous basal birds were known largely from just two-dimensionally preserved specimens from north-eastern China (Jehol Biota), which has hindered our understanding of the early evolution of birds. Here, we present a three-dimensionally-preserved skeleton (FPDM-V-9769) of a basal bird from the Early Cretaceous of Fukui, central Japan. Unique features in the pygostyle and humerus allow the assignment of FPDM-V-9769 to a new taxon, Fukuipteryx prima. FPDM-V-9769 exhibits a set of features comparable to that of other basalmost birds including Archaeopteryx. Osteohistological analyses indicate that FPDM-V-9769 is subadult. Phylogenetic analyses resolve F. prima as a non-ornithothoracine avialan basal to Jeholornis and outgroup of the Pygostylia. This phylogenetic result may imply a complex evolutionary history of basal birds. To our knowledge, FPDM-V-9769 represents the first record of the Early Cretaceous non-ornithothoracine avialan outside of the Jehol Biota and increases our understanding of their diversity and distribution during the time.

scholarly journals A basal thunnosaurian from Iraq reveals disparate phylogenetic origins for Cretaceous ichthyosaurs

2018 ◽  
Author(s):  
Valentin Fischer ◽  
Darren Naish ◽  
Jeff Liston ◽  
Robert M Appleby ◽  
James B Riding ◽  
...  
Keyword(s):  
Middle East ◽  
Early Cretaceous ◽  
Late Jurassic ◽  
Evolutionary History ◽  
Early Jurassic ◽  
Late Triassic ◽  
Low Diversity ◽  
History Of

Cretaceous ichthyosaurs have typically been considered a small, homo- geneous assemblage sharing a common Late Jurassic ancestor. Their low diversity and disparity have been interpreted as indicative of a decline lead- ing to their Cenomanian extinction. We describe the first post-Triassic ichthyosaur from the Middle East, Malawania anachronus gen. et sp. nov. from the Early Cretaceous of Iraq, and re-evaluate the evolutionary history of parvipelvian ichthyosaurs via phylogenetic and cladogenesis rate ana- lyses. Malawania represents a basal grade in thunnosaurian evolution that arose during a major Late Triassic radiation event and was previously thought to have gone extinct during the Early Jurassic. Its pectoral mor- phology appears surprisingly archaic, retaining a forefin architecture similar to that of its Early Jurassic relatives. After the initial latest Triassic radiation of early thunnosaurians, two subsequent large radiations pro- duced lineages with Cretaceous representatives, but the radiation events themselves are pre-Cretaceous. Cretaceous ichthyosaurs therefore include distantly related lineages, with contrasting evolutionary histories, and appear more diverse and disparate than previously supposed.

scholarly journals Nephromyces represents a diverse and novel lineage of the Apicomplexa that has retained apicoplasts

2019 ◽  
Author(s):  
Sergio A Muñoz-Gómez ◽  
Keira Durnin ◽  
Laura Eme ◽  
Christopher Paight ◽  
Christopher E Lane ◽  
...  
Keyword(s):  
Life Style ◽  
Metabolic Pathways ◽  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Phylogenetic Position ◽  
Biosynthetic Pathways ◽  
History Of ◽  
Sea Squirts ◽  
Shed Light ◽  
Apicoplast Genome

Abstract A most interesting exception within the parasitic Apicomplexa is Nephromyces, an extracellular, probably mutualistic, endosymbiont found living inside molgulid ascidian tunicates (i.e., sea squirts). Even though Nephromyces is now known to be an apicomplexan, many other questions about its nature remain unanswered. To gain further insights into the biology and evolutionary history of this unusual apicomplexan, we aimed to (1) find the precise phylogenetic position of Nephromyces within the Apicomplexa, (2) search for the apicoplast genome of Nephromyces, and (3) infer the major metabolic pathways in the apicoplast of Nephromyces. To do this, we sequenced a metagenome and a metatranscriptome from the molgulid renal sac, the specialized habitat where Nephromyces thrives. Our phylogenetic analyses of conserved nucleus-encoded genes robustly suggest that Nephromyces is a novel lineage sister to the Hematozoa, which comprises both the Haemosporidia (e.g., Plasmodium) and the Piroplasmida (e.g., Babesia and Theileria). Furthermore, a survey of the renal sac metagenome revealed 13 small contigs that closely resemble the genomes of the non-photosynthetic reduced plastids, or apicoplasts, of other apicomplexans. We show that these apicoplast genomes correspond to a diverse set of most closely related but genetically divergent Nephromyces lineages that co-inhabit a single tunicate host. In addition, the apicoplast of Nephromyces appears to have retained all biosynthetic pathways inferred to have been ancestral to parasitic apicomplexans. Our results shed light on the evolutionary history of the only probably mutualistic apicomplexan known, Nephromyces, and provide context for a better understanding of its life style and intricate symbiosis.

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