scholarly journals A new southern Laramidian ankylosaurid, Akainacephalus johnsoni gen. et sp. nov., from the upper Campanian Kaiparowits Formation of southern Utah, USA

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5016 ◽  
Author(s):  
Jelle P. Wiersma ◽  
Randall B. Irmis

A partial ankylosaurid skeleton from the upper Campanian Kaiparowits Formation of southern Utah is recognized as a new taxon, Akainacephalus johnsoni, gen. et sp. nov. The new taxon documents the first record of an associated ankylosaurid skull and postcranial skeleton from the Kaiparowits Formation. Preserved material includes a complete skull, much of the vertebral column, including a complete tail club, a nearly complete synsacrum, several fore- and hind limb elements, and a suite of postcranial osteoderms, making Akainacephalus johnsoni the most complete ankylosaurid from the Late Cretaceous of southern Laramidia. Arrangement and morphology of cranial ornamentation in Akainacephalus johnsoni is strikingly similar to Nodocephalosaurus kirtlandensis and some Asian ankylosaurids (e.g., Saichania chulsanensis, Pinacosaurus grangeri, and Minotaurasaurus ramachandrani); the cranium is densely ornamented with symmetrically arranged and distinctly raised ossified caputegulae which are predominantly distributed across the dorsal and dorsolateral regions of the nasals, frontals, and orbitals. Cranial caputegulae display smooth surface textures with minor pitting and possess a distinct conical to pyramidal morphology which terminates in a sharp apex. Character analysis suggests a close phylogenetic relationship with N. kirtlandensis, M. ramachandrani, Tarchia teresae, and S. chulsanensis, rather than with Late Cretaceous northern Laramidian ankylosaurids (e.g., Euoplocephalus tutus, Anodontosaurus lambei, and Ankylosaurus magniventris). These new data are consistent with evidence for distinct northern and southern biogeographic provinces in Laramidia during the late Campanian. The addition of this new ankylosaurid taxon from southern Utah enhances our understanding of ankylosaurid diversity and evolutionary relationships. Potential implications for the geographical distribution of Late Cretaceous ankylosaurid dinosaurs throughout the Western Interior suggest multiple time-transgressive biogeographic dispersal events from Asia into Laramidia.

2014 ◽  
Vol 35 (1) ◽  
pp. 1-26 ◽  
Author(s):  
Andrea Concheyro ◽  
Andrea Caramés ◽  
Cecilia R. Amenábar ◽  
Marina Lescano

AbstractMicropaleontological and palynological samples from three Cenozoic diamictites at Cape Lamb, Vega Island, James Ross Basin were analysed. Fossiliferous samples yielded reworked and autochthonous assemblages of Mesozoic calcareous nanno− fossils, impoverished Cretaceous foraminifera together with Neogene species, as well as Late Cretaceous dinoflagellate cysts, pollen, spores and abundant Cenozoic micro− foraminiferal linings. The recovered nannoflora indicates Early Cretaceous (Hauteri− vian-Albian) and Late Cretaceous (Santonian-Early Campanian) ages, suggesting an in− tensive reworking of marine sediments. The presence of the Early Cretaceous species Nannoconus circularis Deres et Acheriteguy in the diamictite represents its first record for the James Ross Basin. The scarce foraminiferal fauna includes Pullenia jarvisi Cushman, which indicates reworking from lower Maastrichtian-lower Paleocene sediments, and also the Neogene autochthonous Trochammina sp. aff. T. intermedia. The in− ner−organic layer observed inside this specimen appears to be identical to microfora− miniferal linings recovered from the same sample. Palynomorphs found in the studied samples suggest erosion from the underlying Snow Hill Island and the Lopez de Bertodano Formation beds (upper Campanian-upper Maastrichtian). These recovered assemblages indicate either different periods of deposition or reworking from diverse sources during Cenozoic glaciation, originating in James Ross Island and the Antarctic Peninsula with the influence of local sediment sources.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yoshitsugu Kobayashi ◽  
Ryuji Takasaki ◽  
Katsuhiro Kubota ◽  
Anthony R. Fiorillo

AbstractHere we describe a partial hadrosaurid skeleton from the marine Maastrichtian Kita-ama Formation in Japan as a new taxon, Yamatosaurus izanagii gen. et sp. nov., based on unique characters in the dentition. Our phylogenetic analysis demonstrates Yamatosaurus izanagii belongs to Hadrosauridae, composed of Hadrosaurus foulkii + (Yamatosaurus izanagii + (Saurolophinae + Lambeosaurinae)). The coracoid lacks a biceps tubercle as in non-hadrosaurid hadrosauroids, suggesting its presence is a key feature for the clade of Saurolophinae and Lambeosaurinae. The evolutionary rates analysis further supports that shoulder and forelimb features, which are likely to have been involved in locomotion, were important for the early evolution of Hadrosauridae. Our biogeographic analyses show that basal hadrosaurids were widely distributed in Asia and Appalachia, that the clade of Saurolophinae and Lambeosaurinae originated in Asia, and that eastern Asia may have served as a refugium of relict hadrosauroid taxa such as Plesiohadros djadokhtaensis, Tanius sinensis, and Yamatosaurus izanagii during the Late Cretaceous. The contemporaneous occurrence of basal (Yamatosaurus izanagii) and derived (Kamuysaurus japonicus) hadrosaurids during the Maastrichtian in Japan is the first record in Asia. Because of the long geographical distance between these localities, they likely did not co-exist, but instead demonstrate some level of provinciality.


2021 ◽  
Vol 8 (9) ◽  
pp. 210923
Author(s):  
Kohei Tanaka ◽  
Otabek Ulugbek Ogli Anvarov ◽  
Darla K. Zelenitsky ◽  
Akhmadjon Shayakubovich Ahmedshaev ◽  
Yoshitsugu Kobayashi

Carcharodontosauria is a group of medium to large-sized predatory theropods, distributed worldwide during the Cretaceous. These theropods were probably the apex predators of Asiamerica in the early Late Cretaceous prior to the ascent of tyrannosaurids, although few Laurasian species are known from this time due to a poor rock record. Here, we describe Ulughbegsaurus uzbekistanensis gen. et sp. nov. from the early Late Cretaceous (Turonian) of Central Asia, which represents the first record of a Late Cretaceous carcharodontosaurian from the region. This new taxon is represented by a large, isolated maxilla from the Bissekty Formation of the Kyzylkum Desert, the Republic of Uzbekistan, a formation yielding a rich and diverse assemblage of dinosaurs and other vertebrates from fragmentary remains. Comparison of the maxilla with that of other allosauroids indicates Ulughbegsaurus was 7.5–8 m in body length and greater than 1000 kg in body mass, suggesting it was the previously unrecognized apex predator of the Bissekty ecosystem while smaller known tryannosauroids and dromaeosaurids were probable mesopredators. The discovery of Ulughbegsaurus records the geologically latest stratigraphic co-occurrence of carcharodontosaurid and tyrannosauroid dinosaurs from Laurasia, and evidence indicates carcharodontosaurians remained the dominant predators relative to tyrannosauroids, at least in Asia, as late as the Turonian.


Fossil Record ◽  
2003 ◽  
Vol 6 (1) ◽  
pp. 161-168
Author(s):  
A. López-Arbarello ◽  
G. Arratia ◽  
M. A. Tunik

Some isolated acanthomorph remains and a new taxon of perciform fishes, <i>Saldenioichthys remotus</i> gen. et sp. nov., from the Maastrichtian Saldeño Formation of Mendoza province, Argentina, are described and their systematic affinities are discussed. The new taxon is represented by a single incomplete, but well preserved postcranial skeleton. With the exception of a fully developed neural spine on the second preural centrum, it agrees with the generalized skeletal features of basal percoids, in particular the generalized perciform caudal skeleton. The only other Mesozoic perciform skeletal remains known so far are <i>Nardoichthys</i>, from the upper Campanian-lower Maastrichtian of Nardo (Italy) and <i>Eoserranus</i> from the Upper Cretaceous Lameta Formation (India). Therefore, the new perciform taxon from the Saldeño Formation represents one of the oldest members of this group, and due to its peculiar combination of primitive and derived characters, it raises several questions regarding character evolution on this lineage. <br><br> Es werden einige isolierte Reste acanthomorpher Fische sowie ein neues Taxon der Perciformes, <i>Saldenioichthys</i> remotus gen. et sp. nov., aus dem Maastricht der Saldeño Formation in der Provinz Mendoza, Argentinien, werden beschrieben und ihre systematische Stellung wird diskutiert. Das neue Taxon ist durch ein einziges, unvollständiges, aber gut erhaltenes postkraniales Skelett repräsentiert. Mit Ausnahme eines vollstandig ausgebildeten Dornfortsatzes auf dem ersten präuralen Zentrum stimmt es mit der generalisierten Skelettmorphologie basaler Percoiden überein, insbesondere mit dem generalisierten perciformen Caudal-Skelett. Die einzigen anderen Skelettreste von Perciformen aus dem Mesozoikum sind <i>Nardoichthys</i> aus dem Ober-Campan/Unter-Maastricht von Nardo, Italien, und <i>Eoserranus</i> aus der Oberkreide der Lameta Formation, Indien, und die Gruppe ist ansonsten praktisch nur aus känozoischen Sedimenten bekannt. Somit stellt das neue Taxon aus der Saldeño Formation einen der ältesten Nachweise dieser Gruppe dar, und wirft aufgrund seiner ungewöhnlichen Kombination primitiver und fortschrittlicher Merkmale einige Fragen zur Merkmalsevolution in dieser Linie auf. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.20030060109" target="_blank">10.1002/mmng.20030060109</a>


2013 ◽  
Vol 280 (1766) ◽  
pp. 20131186 ◽  
Author(s):  
Scott D. Sampson ◽  
Eric K. Lund ◽  
Mark A. Loewen ◽  
Andrew A. Farke ◽  
Katherine E. Clayton

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.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7562
Author(s):  
Tobias Massonne ◽  
Davit Vasilyan ◽  
Márton Rabi ◽  
Madelaine Böhme

During systematic paleontological surveys in the Na Duong Basin in North Vietnam between 2009 and 2012, well-preserved fossilized cranial and postcranial remains belonging to at least 29 individuals of a middle to late Eocene (late Bartonian to Priabonian age (39–35 Ma)) alligatoroid were collected. Comparative anatomical study of the material warrants the diagnosis of a new taxon, Orientalosuchus naduongensis gen. et sp. nov. The combined presence of an enlarged fifth maxillary tooth, prominent preorbital ridges, a large supraoccipital exposure on the skull table, a palatine-pterygoid suture anterior to the posterior end of the suborbital fenestra, and a pterygoid forming a neck surrounding the choana is unique to this species. Unlike previous phylogenies, our parsimony analysis recovers a monophyletic Late Cretaceous to Paleogene East to Southeastern Asian alligatoroid group, here named Orientalosuchina. The group includes Orientalosuchus naduongensis, Krabisuchus siamogallicus, Eoalligator chunyii, Jiangxisuchus nankangensis and Protoalligator huiningensis, all of them sharing a medial shifted quadrate foramen aerum. The recognition of this clade indicates at least two separate dispersal events from North America to Asia: one during the Late Cretaceous by Orientalosuchina and one by the ancestor of Alligator sinensis during the Paleogene or Neogene, the timing of which is poorly constrained.


Geobios ◽  
2021 ◽  
Author(s):  
Yasmani Ceballos Izquierdo ◽  
Lázaro W. Viñola-López ◽  
Carlos Rafael Borges-Sellén ◽  
Alberto F. Arano-Ruiz
Keyword(s):  

2021 ◽  
Vol 53 (1) ◽  
pp. 95-101
Author(s):  
Gintaras Kantvilas

AbstractThe lichen genus Lecanactis Körb. in Tasmania comprises six species: L. abietina (Ach.) Körb., which is widespread and pan-temperate; L. latispora Egea & Torrente and L. neozelandica Egea & Torrente, both shared with New Zealand and with the former recorded here from the Auckland Islands for the first time; L. mollis (Stirt.) Frisch & Ertz, shared with Victoria and New Zealand; L. aff. dilleniana (Ach.) Körb., a European species recorded provisionally for Tasmania on the basis of several sterile collections; L. scopulicola Kantvilas, which is described here as new to science and apparently a Tasmanian endemic. This new taxon occurs in rocky underhangs and is characterized by a thick, leprose thallus containing schizopeltic acid, and 3-septate ascospores, 19–30 × 4.5–6 μm. Short descriptions and a discussion of distribution and ecology are given for all species. A key for all 11 Australian species of the genus is provided, including L. subfarinosa (C. Knight) Hellb. and L. tibelliana Egea & Torrente, which are recorded for Australia for the first time, and L. platygraphoides (Müll.Arg.) Zahlbr., a first record for New South Wales. Lecanactis spermatospora Egea & Torrente and L. sulphurea Egea & Torrente are also included.


Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 354
Author(s):  
Davide Badano ◽  
Qingqing Zhang ◽  
Michela Fratini ◽  
Laura Maugeri ◽  
Inna Bukreeva ◽  
...  

Lebambromyia sacculifera sp. nov. is described from Late Cretaceous amber from Myanmar, integrating traditional observation techniques and X-ray phase contrast microtomography. Lebambromyia sacculifera is the second species of Lebambromyia after L. acrai Grimaldi and Cumming, described from Lebanese amber (Early Cretaceous), and the first record of this taxon from Myanmar amber, considerably extending the temporal and geographic range of this genus. The new specimen bears a previously undetected set of phylogenetically relevant characters such as a postpedicel sacculus and a prominent clypeus, which are shared with Ironomyiidae and Eumuscomorpha. Our cladistic analyses confirmed that Lebambromyia represented a distinct monophyletic lineage related to Platypezidae and Ironomyiidae, though its affinities are strongly influenced by the interpretation and coding of the enigmatic set of features characterizing these fossil flies.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Federico J. Degrange ◽  
Diego Pol ◽  
Pablo Puerta ◽  
Peter Wilf

AbstractHere we present the first record of a stem-Coracii outside the Holarctic region, found in the early Eocene of Patagonia at the Laguna del Hunco locality. Ueekenkcoracias tambussiae gen. et sp. nov. consists of an incomplete right hind limb that presents the following combination of characters, characteristic of Coracii: relatively short and stout tibiotarsus, poorly developed crista cnemialis cranialis, short and wide tarsometatarsus, with the tuberositas m. tibialis cranialis located medially on the shaft, and curved and stout ungual phalanges. Although the presence of a rounded and conspicuous foramen vasculare distale and the trochlea metatarsi II strongly deflected medially resemble Primobucconidae, a fossil group only found in the Eocene of Europe and North America, our phylogenetic analysis indicates the new taxon is the basalmost known Coracii. The unexpected presence of a stem-Coracii in the Eocene of South America indicates that this clade had a more widespread distribution than previously hypothesized, already extending into the Southern Hemisphere by the early Eocene. Ueekenkcoracias tambussiae represents new evidence of the increasing diversity of stem lineages of birds in the Eocene. The new material provides novel morphological data for understanding the evolutionary origin and radiation of rollers and important data for estimates of the divergence time of the group.


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