Picopsis pattersoni, n.gen. and sp., an unusual therian from the Upper Cretaceous of Alberta, and the classification of primitive tribosphenic mammals

1980 ◽  
Vol 17 (11) ◽  
pp. 1489-1498 ◽  
Author(s):  
Richard C. Fox
Keyword(s):  
Upper Cretaceous ◽  
Therian Mammal ◽  
New Family ◽  
Milk River Formation

A new therian mammal of primitive tribosphenic grade is described from the Upper Milk River Formation (Upper Cretaceous) of Alberta, Canada, and its relationships to other primitive tribosphenic therians are discussed. The new therian and its presumed nearest relatives form the basis of a new family within the Order Aegialodontia. A revised classification of the Infraclass Tribotheria is presented.

A Primitive Therian Mammal from the Upper Cretaceous of Alberta

1972 ◽  
Vol 9 (11) ◽  
pp. 1479-1494 ◽  
Author(s):  
Richard C. Fox
Keyword(s):  
New Species ◽  
Late Cretaceous ◽  
Lower Cretaceous ◽  
Upper Cretaceous ◽  
Mammalian Species ◽  
Therian Mammal ◽  
Incertae Sedis ◽  
Milk River Formation

The discovery of tribosphenic molars of primitive construction in the Upper Milk River Formation (early Campanian), Alberta, documents the occurrence of a relict middle Late Cretaceous mammalian species that shows closest dental resemblance to Lower Cretaceous therians of metatherian–eutherian grade now classified as Theria, incertae sedis. The molar crowns of This new species have a wide stylar shelf, small, low protocone, distal trigonid crest, and lack conules and a shelf-like preparaconule crista mesial to the paracone; these and other coronal features indicate a more primitive level of molar evolution than known for Cretaceous Metatheria or Eutheria. Although too late in time to be ancestral to Cretaceous higher Theria, the new Milk River species may clarify aspects of their origin.

Three new species, two new genera, and new family Biphragmosagittidae (Сhaetognatha) from Southwest Pacific Ocean

2011 ◽  
Vol 20 (1) ◽  
pp. 161-173
Author(s):  
A.P. Kassatkina
Keyword(s):  
New Species ◽  
Type Species ◽  
Morphological Characters ◽  
The Body ◽  
New Order ◽  
New Genera ◽  
New Family ◽  
The Family ◽  
Three New Species

Resuming published and own data, a revision of classification of Chaetognatha is presented. The family Sagittidae Claus & Grobben, 1905 is given a rank of subclass, Sagittiones, characterised, in particular, by the presence of two pairs of sac-like gelatinous structures or two pairs of fins. Besides the order Aphragmophora Tokioka, 1965, it contains the new order Biphragmosagittiformes ord. nov., which is a unique group of Chaetognatha with an unusual combination of morphological characters: the transverse muscles present in both the trunk and the tail sections of the body; the seminal vesicles simple, without internal complex compartments; the presence of two pairs of lateral fins. The only family assigned to the new order, Biphragmosagittidae fam. nov., contains two genera. Diagnoses of the two new genera, Biphragmosagitta gen. nov. (type species B. tarasovi sp. nov. and B. angusticephala sp. nov.) and Biphragmofastigata gen. nov. (type species B. fastigata sp. nov.), detailed descriptions and pictures of the three new species are presented.

scholarly journals PseudoGTPase domains in p190RhoGAP proteins: a mini-review

2018 ◽  
Vol 46 (6) ◽  
pp. 1713-1720 ◽  
Author(s):  
Amy L. Stiegler ◽  
Titus J. Boggon
Keyword(s):  
Family Members ◽  
Small Gtpases ◽  
Small Gtpase ◽  
Signaling Proteins ◽  
New Family ◽  
Gtpase Activating Proteins ◽  
Rho Family ◽  
Biochemical Analyses ◽  
Catalytic Cleft

Pseudoenzymes generally lack detectable catalytic activity despite adopting the overall protein fold of their catalytically competent counterparts, indeed ‘pseudo’ family members seem to be incorporated in all enzyme classes. The small GTPase enzymes are important signaling proteins, and recent studies have identified many new family members with noncanonical residues within the catalytic cleft, termed pseudoGTPases. To illustrate recent discoveries in the field, we use the p190RhoGAP proteins as an example. p190RhoGAP proteins (ARHGAP5 and ARHGAP35) are the most abundant GTPase activating proteins for the Rho family of small GTPases. These are key regulators of Rho signaling in processes such as cell migration, adhesion and cytokinesis. Structural biology has complemented and guided biochemical analyses for these proteins and has allowed discovery of two cryptic pseudoGTPase domains, and the re-classification of a third, previously identified, GTPase-fold domain as a pseudoGTPase. The three domains within p190RhoGAP proteins illustrate the diversity of this rapidly expanding pseudoGTPase group.

Parataxonomic classification of ornithoid eggshell fragments from the Oldman Formation (Judith River Group; Upper Cretaceous), southern Alberta

1996 ◽  
Vol 33 (12) ◽  
pp. 1655-1667 ◽  
Author(s):  
Darla K. Zelenitsky ◽  
L. V. Hills ◽  
Philip J. Currie
Keyword(s):  
Late Cretaceous ◽  
Shell Thickness ◽  
Upper Cretaceous ◽  
Theropod Dinosaur ◽  
Surface Sculpture ◽  
External Zone ◽  
Theropod Dinosaurs ◽  
Southern Alberta ◽  
The Family

Examination of a large number of eggshell fragments collected from the Oldman Formation of southern Alberta reveals a greater ootaxonomic diversity than is known from complete eggs or clutches. Three new oogenera and oospecies of the ornithoid-ratite morphotype and one of the ornithoid-prismatic morphotype are established, based on the eggshell fragments. Porituberoolithus warnerensis oogen. et oosp. nov. and Continuoolithus canadensis oogen. et oosp. nov. have a microstructure similar to that of elongatoolithid eggs of theropod dinosaurs. Tristraguloolithus cracioides oogen. et oosp. nov. and Dispersituberoolithus exilis oogen. et oosp. nov. possess an external zone and thus have a microstructure like modern avian eggshell. Tristraguloolithus has a shell thickness, microstructure, and surface sculpture similar to those of recent bird eggshell of the family Cracidae (order Galliformes). Dispersituberoolithus exhibits the primitive or normal eggshell condition of some recent neognathous avian taxa. The ootaxa described indicate a diversity of both avian and theropod dinosaur egg layers within Devil's Coulee and Knight's Ranch, southern Alberta, during the Late Cretaceous.

scholarly journals Machine learning classification of new asteroid families members

2020 ◽  
Author(s):  
Valerio Carruba
Keyword(s):  
Machine Learning ◽  
Family Members ◽  
Classification Algorithms ◽  
New Members ◽  
Machine Learning Classification ◽  
New Family ◽  
Robotic Telescope ◽  
Traditional Approaches ◽  
Asteroid Families

<p>Asteroid families are groups of asteroids that are the product of collisions or of the rotational fission of a parent object.  These groups are mainly identified in proper elements or frequencies domains.   Because of robotic telescope surveys, the number of known asteroids has increased from about 10,000 in the early 90's to more than 750,000 nowadays. Traditional approaches for identifying new members of asteroid families, like the hierarchical clustering method (HCM), may   struggle to keep up with the growing rate of new discoveries. Here we used machine learning classification algorithms to identify new family members based on the orbital distribution in proper (a,e,sin(i)) of previously known family constituents. We compared the outcome of nine classification algorithms from stand alone and ensemble approaches.  The Extremely Randomized Trees (ExtraTree) method had the highest precision, enabling to  retrieve up to 97% of family members identified with standard HCM.</p>

scholarly journals Classification of the Asian non-marine Cretaceous System

1984 ◽  
Vol 33 ◽  
pp. 115-122
Author(s):  
Guo Fuxiang
Keyword(s):  
Upper Cretaceous ◽  
Yellowish Green

The Asian non-marine Cretaceous System may be divided into two geographical provinces: a southern one, dominated by elastic red salt-bearing formations, and a northern one, dominated by elastic grey, yellowish green and black formations containing coal (kukersit). Vertically, on the basis of three trigonioi­dacean assemblages (bivalves), the System may be subdivided into Lower, Middle and Upper Cretaceous, three provincial series exhibiting this tripartite character. 4 zones and 6 subzones of the known trigonioi­daceans are tentatively presented.

Back to the Future? Molecules Take Us Back to the 1925 Classification of the Lembophyllaceae (Bryopsida)

2009 ◽  
Vol 34 (3) ◽  
pp. 443-454 ◽  
Author(s):  
Dietmar Quandt ◽  
Sanna Huttunen ◽  
Ray Tangney ◽  
Michael Stech
Keyword(s):  
Single Species ◽  
Molecular Data ◽  
Nuclear Ribosomal Dna ◽  
New Family ◽  
Morphological Studies ◽  
The Family ◽  
Family Level ◽  
Plastid Markers ◽  
Pleurocarpous Moss

Although the Lembophyllaceae has undergone considerable revision during the last century, the generic and familial level relationships of this pleurocarpous moss family are still poorly understood. To address this problem, a generic revision of the Lembophyllaceae based on molecular data was undertaken. We analyzed two plastid markers, the trnL-trnF and the psbT-psbH region in combination with the ITS2 of nuclear ribosomal DNA. The molecular data reveal that the current circumscription of the family is too narrow and that several genera previously placed in the Lembophyllaceae should be reincluded. The family includes: Bestia, Camptochaete, Dolichomitra, Dolichomitriopsis, Fallaciella, Fifea, Isothecium, Lembophyllum, Looseria stat. nov., Pilotrichella, Rigodium, Tripterocladium, and Weymouthia. Looseria contains a single species: Looseria orbiculata comb. nov. Acrocladium is excluded and provisionally accommodated in the Lepyrodontaceae. Generic limits supported by the molecular data support a return to the early twentieth century family concept of Brotherus. The analyses indicate that the segregate genus Orthostichella is distinct from its parent genus Pilotrichella, probably at the family level. Whereas Pilotrichella is resolved within the Lembophyllaceae, Orthostichella clusters with Porotrichum and Porothamnium forming a clade (OPP-clade) sister to the remaining Neckeraceae and Lembophyllaceae. Hence, the Neckeraceae is paraphyletic. Recognition of the OPP-clade as a new family is desirable but awaits the results of detailed ongoing morphological studies.

A new, unusual therian mammal from the Upper Cretaceous of Saskatchewan, Canada

2007 ◽  
Vol 28 (5) ◽  
pp. 821-829 ◽  
Author(s):  
Richard C. Fox ◽  
Craig S. Scott ◽  
Harold N. Bryant
Keyword(s):  
Upper Cretaceous ◽  
Therian Mammal
Sign in / Sign up

Export Citation Format

Share Document