scholarly journals A new family of diprotodontian marsupials from the latest Oligocene of Australia and the evolution of wombats, koalas, and their relatives (Vombatiformes)

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Robin M. D. Beck ◽  
Julien Louys ◽  
Philippa Brewer ◽  
Michael Archer ◽  
Karen H. Black ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Body Size ◽  
South Australia ◽  
Morphological Diversity ◽  
New Taxon ◽  
Ancestral State ◽  
Late Oligocene ◽  
Postcranial Skeleton ◽  
New Family ◽  
Australian Marsupial

Abstract We describe the partial cranium and skeleton of a new diprotodontian marsupial from the late Oligocene (~26–25 Ma) Namba Formation of South Australia. This is one of the oldest Australian marsupial fossils known from an associated skeleton and it reveals previously unsuspected morphological diversity within Vombatiformes, the clade that includes wombats (Vombatidae), koalas (Phascolarctidae) and several extinct families. Several aspects of the skull and teeth of the new taxon, which we refer to a new family, are intermediate between members of the fossil family Wynyardiidae and wombats. Its postcranial skeleton exhibits features associated with scratch-digging, but it is unlikely to have been a true burrower. Body mass estimates based on postcranial dimensions range between 143 and 171 kg, suggesting that it was ~5 times larger than living wombats. Phylogenetic analysis based on 79 craniodental and 20 postcranial characters places the new taxon as sister to vombatids, with which it forms the superfamily Vombatoidea as defined here. It suggests that the highly derived vombatids evolved from wynyardiid-like ancestors, and that scratch-digging adaptations evolved in vombatoids prior to the appearance of the ever-growing (hypselodont) molars that are a characteristic feature of all post-Miocene vombatids. Ancestral state reconstructions on our preferred phylogeny suggest that bunolophodont molars are plesiomorphic for vombatiforms, with full lophodonty (characteristic of diprotodontoids) evolving from a selenodont morphology that was retained by phascolarctids and ilariids, and wynyardiids and vombatoids retaining an intermediate selenolophodont condition. There appear to have been at least six independent acquisitions of very large (>100 kg) body size within Vombatiformes, several having already occurred by the late Oligocene.

scholarly journals Oldest cingulate skulls provide congruence between morphological and molecular scenarios of armadillo evolution

2011 ◽  
Vol 278 (1719) ◽  
pp. 2791-2797 ◽  
Author(s):  
Guillaume Billet ◽  
Lionel Hautier ◽  
Christian de Muizon ◽  
Xavier Valentin
Keyword(s):  
Phylogenetic Analysis ◽  
Fossil Record ◽  
Phylogenetic Analyses ◽  
Typical Case ◽  
New Taxon ◽  
Late Oligocene ◽  
Phylogenetic Studies ◽  
Molecular Phylogenetic ◽  
Early Neogene ◽  
Group A

The cingulates of the mammalian order Xenarthra present a typical case of disagreement between molecular and morphological phylogenetic studies. We report here the discovery of two new skulls from the Late Oligocene Salla Beds of Bolivia (approx. 26 Ma), which are the oldest known well-preserved cranial remains of the group. A new taxon is described: Kuntinaru boliviensis gen. et sp. nov. A phylogenetic analysis clusters K. boliviensis together with the armadillo subfamily Tolypeutinae. These skulls document an early spotty occurrence for the Tolypeutinae at 26 Ma, in agreement with the temporal predictions of previous molecular studies. The fossil record of tolypeutines is now characterized by a unique occurrence in the Late Oligocene, and a subsequent 12 Myr lack in the fossil record. It is noteworthy that the tolypeutines remain decidedly marginal in the Late Palaeogene and Early Neogene deposits, whereas other cingulate groups diversify. Also, the anatomical phylogenetic analysis herein, which includes K. boliviensis , is congruent with recent molecular phylogenetic analyses. Kuntinaru boliviensis is the oldest confident calibration point available for the whole Cingulata.

scholarly journals A new large-bodied Pliocene seal with unusual cutting teeth

2020 ◽  
Vol 7 (11) ◽  
pp. 201591
Author(s):  
James P. Rule ◽  
Justin W. Adams ◽  
Douglass S. Rovinsky ◽  
David P. Hocking ◽  
Alistair R. Evans ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
North Atlantic ◽  
Taxonomic Status ◽  
Diagnostic Value ◽  
New Taxon ◽  
Ancestral State ◽  
The North ◽  
Body Sizes ◽  
The Usa ◽  
The North Atlantic

Today, monachine seals display the largest body sizes in pinnipeds. However, the evolution of larger body sizes has been difficult to assess due to the murky taxonomic status of fossil seals, including fossils referred to Callophoca obscura , a species thought to be present on both sides of the North Atlantic during the Neogene. Several studies have recently called into question the taxonomic validity of these fossils, especially those from the USA, as the fragmentary lectotype specimen from Belgium is of dubious diagnostic value. We find that the lectotype isolated humerus of C. obscura is too uninformative; thus, we designate C. obscura as a nomen dubium. More complete cranial and postcranial specimens from the Pliocene Yorktown Formation are described as a new taxon, Sarcodectes magnus . The cranial specimens display adaptations towards an enhanced ability to cut or chew prey that are unique within Phocidae, and estimates indicate S. magnus to be around 2.83 m in length. A parsimony phylogenetic analysis found S. magnus is a crown monachine. An ancestral state estimation of body length indicates that monachines did not have a remarkable size increase until the evolution of the lobodontins and miroungins.

scholarly journals Late Oligocene–Miocene non-lunulate sand dollars of South America: Revision of abertellid taxa and descriptions of two new families, two new genera, and a new species

Zootaxa ◽  
2018 ◽  
Vol 4369 (3) ◽  
pp. 301 ◽  
Author(s):  
RICH MOOI ◽  
SERGIO A. MARTÍNEZ ◽  
CLAUDIA J. DEL RÍO ◽  
MARIA INÊS FEIJÓ RAMOS
Keyword(s):  
South American ◽  
New Taxon ◽  
Late Oligocene ◽  
South American Species ◽  
New Family ◽  
The Status ◽  
The Common ◽  
Sand Dollars ◽  
The Relationship ◽  
A New Species

Material for all seven South American species of late Oligocene and Miocene scutelliform, non-lunulate sand dollars (Echinoidea: Clypeasteroida) was examined, resulting in revision of several taxa, and description of a new family, Placatenellidae n. fam., to house Placatenella n. gen. and Camachoaster n. gen. Known only from the state of Pará, Brazil, and previously described as a member of Abertella Durham, 1953, A. complanata Brito, 1981 is redescribed on the basis of analysis of the holotype and subsequently described material from the same region. A. complanata is removed from synonymy with A. pirabensis (Marchesini Santos, 1958), and transferred as the type species of Placatenella n. gen. A new taxon, Camachoaster n. gen., is described to hold C. maquedensis n. sp. The Abertellidae Durham, 1955 is revised and the concept of the genus Abertella restricted to include only those forms with a posterior notch and all interambulacra discontinuous, including A. pirabensis, which is redescribed from the only known specimen, confirming that this species lacks any trace of an anal lunule but possesses features fully congruent with its placement in Abertella. Iheringiellidae n. fam. is established to house the common but taxonomically challenging taxon, Iheringiella Berg, 1898. New data on the occurrence and location of the types of Iheringiella are discussed, and comments on the status of Eoscutella mirandae Parma, 1985 provided. A tabular key to all seven South American non-lunulates is given, along with discussion of the relationship between the posterior notch and the anal lunule. 

scholarly journals A gigantic bird from the Upper Cretaceous of Central Asia

2011 ◽  
Vol 8 (1) ◽  
pp. 97-100 ◽  
Author(s):  
Darren Naish ◽  
Gareth Dyke ◽  
Andrea Cau ◽  
François Escuillié ◽  
Pascal Godefroit
Keyword(s):  
Phylogenetic Analysis ◽  
Body Size ◽  
Central Asia ◽  
Late Cretaceous ◽  
Upper Cretaceous ◽  
Large Body ◽  
New Taxon ◽  
Ecological Diversity ◽  
Large Body Size ◽  
Fossil Bird

We describe an enormous Late Cretaceous fossil bird from Kazakhstan, known from a pair of edentulous mandibular rami (greater than 275 mm long), which adds significantly to our knowledge of Mesozoic avian morphological and ecological diversity. A suite of autapomorphies lead us to recognize the specimen as a new taxon. Phylogenetic analysis resolves this giant bird deep within Aves as a basal member of Ornithuromorpha. This Kazakh fossil demonstrates that large body size evolved at least once outside modern birds (Neornithes) and reveals hitherto unexpected trophic diversity within Cretaceous Aves.

scholarly journals A new species of Proegernia from the Namba Formation in South Australia and the early evolution and environment of Australian egerniine skinks

2021 ◽  
Vol 8 (2) ◽  
pp. 201686
Author(s):  
K. M. Thorn ◽  
M. N. Hutchinson ◽  
M. S. Y. Lee ◽  
N. J. Brown ◽  
A. B. Camens ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Fossil Record ◽  
South Australia ◽  
Early Evolution ◽  
Sister Species ◽  
Total Evidence ◽  
New Taxon ◽  
A New Species

The diverse living Australian lizard fauna contrasts greatly with their limited Oligo-Miocene fossil record. New Oligo-Miocene fossil vertebrates from the Namba Formation (south of Lake Frome, South Australia) were uncovered from multiple expeditions from 2007 to 2018. Abundant disarticulated material of small vertebrates was concentrated in shallow lenses along the palaeolake edges, now exposed on the western of Lake Pinpa also known from Billeroo Creek 2 km northeast. The fossiliferous lens within the Namba Formation hosting the abundant aquatic (such as fish, platypus Obdurodon and waterfowl) and diverse terrestrial (such as possums, dasyuromorphs and scincids) vertebrates and is hereafter recognized as the Fish Lens. The stratigraphic provenance of these deposits in relation to prior finds in the area is also established. A new egerniine scincid taxon Proegernia mikebulli sp. nov. described herein, is based on a near-complete reconstructed mandible, maxilla, premaxilla and pterygoid. Postcranial scincid elements were also recovered with this material, but could not yet be confidently associated with P. mikebulli . This new taxon is recovered as the sister species to P. palankarinnensis , in a tip-dated total-evidence phylogenetic analysis, where both are recovered as stem Australian egerniines. These taxa also help pinpoint the timing of the arrival of scincids to Australia, with egerniines the first radiation to reach the continent.

scholarly journals A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7247 ◽  
Author(s):  
Scott Hartman ◽  
Mickey Mortimer ◽  
William R. Wahl ◽  
Dean R. Lomax ◽  
Jessica Lippincott ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
North America ◽  
Early Cretaceous ◽  
Late Jurassic ◽  
New Taxon ◽  
Morrison Formation ◽  
Postcranial Skeleton ◽  
Avian Flight ◽  
Multiple Alternative ◽  
Limb Proportions

The last two decades have seen a remarkable increase in the known diversity of basal avialans and their paravian relatives. The lack of resolution in the relationships of these groups combined with attributing the behavior of specialized taxa to the base of Paraves has clouded interpretations of the origin of avialan flight. Here, we describeHesperornithoides miesslerigen. et sp. nov., a new paravian theropod from the Morrison Formation (Late Jurassic) of Wyoming, USA, represented by a single adult or subadult specimen comprising a partial, well-preserved skull and postcranial skeleton. Limb proportions firmly establishHesperornithoidesas occupying a terrestrial, non-volant lifestyle. Our phylogenetic analysis emphasizes extensive taxonomic sampling and robust character construction, recovering the new taxon most parsimoniously as a troodontid close toDaliansaurus,Xixiasaurus, andSinusonasus. Multiple alternative paravian topologies have similar degrees of support, but proposals of basal paravian archaeopterygids, avialan microraptorians, andRahonavisbeing closer to Pygostylia than archaeopterygids or unenlagiines are strongly rejected. All parsimonious results support the hypothesis that each early paravian clade was plesiomorphically flightless, raising the possibility that avian flight originated as late as the Late Jurassic or Early Cretaceous.

scholarly journals A remarkable short-snouted horned dinosaur from the Late Cretaceous (late Campanian) of southern Laramidia

2013 ◽  
Vol 280 (1766) ◽  
pp. 20131186 ◽  
Author(s):  
Scott D. Sampson ◽  
Eric K. Lund ◽  
Mark A. Loewen ◽  
Andrew A. Farke ◽  
Katherine E. Clayton
Keyword(s):  
Phylogenetic Analysis ◽  
North America ◽  
Late Cretaceous ◽  
Fossil Record ◽  
Strong Support ◽  
Northern Region ◽  
New Taxon ◽  
Western North America ◽  
Postcranial Skeleton ◽  
Western Interior Seaway

The fossil record of centrosaurine ceratopsids is largely restricted to the northern region of western North America (Alberta, Montana and Alaska). Exceptions consist of single taxa from Utah ( Diabloceratops ) and China ( Sinoceratops ), plus otherwise fragmentary remains from the southern Western Interior of North America. Here, we describe a remarkable new taxon, Nasutoceratops titusi n. gen. et sp., from the late Campanian Kaiparowits Formation of Utah, represented by multiple specimens, including a nearly complete skull and partial postcranial skeleton. Autapomorphies include an enlarged narial region, pneumatic nasal ornamentation, abbreviated snout and elongate, rostrolaterally directed supraorbital horncores. The subrectangular parietosquamosal frill is relatively unadorned and broadest in the mid-region. A phylogenetic analysis indicates that Nasutoceratops is the sister taxon to Avaceratops , and that a previously unknown subclade of centrosaurines branched off early in the group's history and persisted for several million years during the late Campanian. As the first well-represented southern centrosaurine comparable in age to the bulk of northern forms, Nasutoceratops provides strong support for the provincialism hypothesis, which posits that Laramidia—the western landmass formed by inundation of the central region of North America by the Western Interior Seaway—hosted at least two coeval dinosaur communities for over a million years of late Campanian time.

scholarly journals Black spicules from a new interstitial opheliid polychaete Thoracophelia minuta sp. nov. (Annelida: Opheliidae)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Naoto Jimi ◽  
Shinta Fujimoto ◽  
Mami Takehara ◽  
Satoshi Imura
Keyword(s):  
Developmental Biology ◽  
Phylogenetic Analysis ◽  
New Species ◽  
Morphological Diversity ◽  
The Body ◽  
Evolutionary Significance ◽  
Research Subject ◽  
Ecological Diversity ◽  
Coelomic Cavity ◽  
Molecular Phylogenetic

AbstractThe phylum Annelida exhibits high morphological diversity coupled with its extensive ecological diversity, and the process of its evolution has been an attractive research subject for many researchers. Its representatives are also extensively studied in fields of ecology and developmental biology and important in many other biology related disciplines. The study of biomineralisation is one of them. Some annelid groups are well known to form calcified tubes but other forms of biomineralisation are also known. Herein, we report a new interstitial annelid species with black spicules, Thoracophelia minuta sp. nov., from Yoichi, Hokkaido, Japan. Spicules are minute calcium carbonate inclusions found across the body and in this new species, numerous black rod-like inclusions of calcium-rich composition are distributed in the coelomic cavity. The new species can be distinguished from other known species of the genus by these conspicuous spicules, shape of branchiae and body formula. Further, the new species’ body size is apparently smaller than its congeners. Based on our molecular phylogenetic analysis using 18S and 28S sequences, we discuss the evolutionary significance of the new species’ spicules and also the species' progenetic origin.

scholarly journals Filling the Gaps in the Cyanobacterial Tree of Life—Metagenome Analysis of Stigonema ocellatum DSM 106950, Chlorogloea purpurea SAG 13.99 and Gomphosphaeria aponina DSM 107014

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 389
Author(s):  
Pia Marter ◽  
Sixing Huang ◽  
Henner Brinkmann ◽  
Silke Pradella ◽  
Michael Jarek ◽  
...  
Keyword(s):  
Heterotrophic Bacteria ◽  
Morphological Diversity ◽  
Cell Types ◽  
Phylogenetic Position ◽  
Metagenome Analysis ◽  
New Family ◽  
Metagenome Sequencing ◽  
Axenic Strains ◽  
Reliable Classification ◽  
Metagenomic Assembly

Cyanobacteria represent one of the most important and diverse lineages of prokaryotes with an unparalleled morphological diversity ranging from unicellular cocci and characteristic colony-formers to multicellular filamentous strains with different cell types. Sequencing of more than 1200 available reference genomes was mainly driven by their ecological relevance (Prochlorococcus, Synechococcus), toxicity (Microcystis) and the availability of axenic strains. In the current study three slowly growing non-axenic cyanobacteria with a distant phylogenetic positioning were selected for metagenome sequencing in order to (i) investigate their genomes and to (ii) uncover the diversity of associated heterotrophs. High-throughput Illumina sequencing, metagenomic assembly and binning allowed us to establish nearly complete high-quality draft genomes of all three cyanobacteria and to determine their phylogenetic position. The cyanosphere of the limnic isolates comprises up to 40 heterotrophic bacteria that likely coexisted for several decades, and it is dominated by Alphaproteobacteria and Bacteriodetes. The diagnostic marker protein RpoB ensured in combination with our novel taxonomic assessment via BLASTN-dependent text-mining a reliable classification of the metagenome assembled genomes (MAGs). The detection of one new family and more than a dozen genera of uncultivated heterotrophic bacteria illustrates that non-axenic cyanobacteria are treasure troves of hidden microbial diversity.

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