New pantolestids (Mammalia, Eutheria) from the late Paleocene (late middle Tiffanian) Roche Percée local fauna, southeastern Saskatchewan, Canada

2014 ◽  
Vol 88 (6) ◽  
pp. 1199-1211 ◽  
Author(s):  
Brian D. Rankin
Keyword(s):  
Evolutionary History ◽  
Evolutionary Relationship ◽  
Western Canada ◽  
Unique Combination ◽  
Local Fauna ◽  
Late Paleocene ◽  
Early Paleocene ◽  
History Of ◽  
Early Late ◽  
High Diversity

The Pantolestidae are an extinct family of mammals known principally from the early Paleocene to late Oligocene (from approximately 64 to 30 million years ago) of North America and Europe. Although never particularly abundant, pantolestids are relatively well represented in the Eocene and Oligocene, with several taxa known from exceptionally well-preserved skulls and postcranial material. The early evolutionary history of the group, however, similar to that of many contemporaneous mammals, remains comparatively poorly known. The current study reports on several previously undescribed pantolestids from the early late Paleocene (late middle Tiffanian, Ti4) Roche Percée local fauna, Ravenscrag Formation, of southeastern Saskatchewan, Canada.Aatotomus placochtonn. gen. n. sp. resembles the enigmatic pantolestidPaleotomusin having sectorial premolars with well-developed crests and tall, sharp molar trigonids, but differs principally in possessing narrow molar talonids.Besseocetor krausein. sp. shares numerous similarities withB. thomsoniandB. septentrionalisbut differs in being considerably smaller and less robust.Palaeosinopa reclusumn. sp., the oldest species ofPalaeosinopayet discovered, reveals a unique combination of primitive and derived pantolestid features, and supports previous suggestions of a close evolutionary relationship betweenPalaeosinopaandBessoecetor. The new taxa document an unusually high diversity of pantolestids in the Tiffanian of western Canada and provide important new knowledge to the evolutionary history of this group during the Paleocene.

Eudaemonema webbi sp. nov. (Mammalia, Mixodectidae) from the late Paleocene of western Canada: the youngest known mixodectid

2010 ◽  
Vol 47 (12) ◽  
pp. 1451-1462 ◽  
Author(s):  
Craig S. Scott
Keyword(s):  
New Species ◽  
North American ◽  
Western Canada ◽  
South Central ◽  
Late Paleocene ◽  
Early Paleocene ◽  
Stratigraphic Ranges ◽  
A New Species ◽  
Stratigraphic Range

Mixodectidae (Mammalia, Archonta) are an unusual, poorly known family of dermopteran-like mammals that have been discovered at several North American localities of primarily early Paleocene age. Among the three or four recognized mixodectid genera, Eudaemonema Simpson is perhaps one of the least understood, being known from only a few localities of late Torrejonian and earliest Tiffanian age. This paper reports on a new species of Eudaemonema from the late Paleocene of Alberta, Canada, that significantly extends the geographic and stratigraphic ranges of the genus. Eudaemonema webbi sp. nov. is known from middle and late Tiffanian localities in central and south central Alberta, and it represents the youngest and northernmost species of Eudaemonema so far discovered. E. webbi differs from the genotypic species E. cuspidata in being larger and in having a suite of dental characters (e.g., molariform posterior premolars, enlarged molar protocone and hypocone, development of a second grinding platform on the lower molars) that suggests an increased emphasis on grinding during mastication. E. webbi possesses several dental features (e.g., broad, shelf-like molar paraconid–paracristid, lingually shifted molar hypoconulid) that resemble those of cynocephalids (Mammalia, Dermoptera), with these resemblances interpreted herein as convergent. The occurrence of E. webbi at Gao Mine extends the stratigraphic range of Eudaemonema into the late Tiffanian (Ti5) and represents the youngest known record of Mixodectidae.

scholarly journals Evolutionary Relationship between Two Firefly Species,Curtos costipennisandC. okinawanus(Coleoptera, Lampyridae), in the Ryukyu Islands of Japan Revealed by the Mitochondrial and Nuclear DNA Sequences

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Masahiko Muraji ◽  
Norio Arakaki ◽  
Shigeo Tanizaki
Keyword(s):  
Dna Sequences ◽  
Evolutionary History ◽  
Nuclear Dna ◽  
Evolutionary Relationship ◽  
Early Pleistocene ◽  
Ryukyu Islands ◽  
Mtdna Sequences ◽  
Northern Half ◽  
The Ryukyu Islands ◽  
History Of

The phylogenetic relationship, biogeography, and evolutionary history of closely related two firefly species,Curtos costipennisandC. okinawanus, distributed in the Ryukyu Islands of Japan were examined based on nucleotide sequences of mitochondrial (2.2 kb long) and nuclear (1.1-1.2 kb long) DNAs. In these analyses, individuals were divided among three genetically distinct local groups,C. costipennisin the Amami region,C. okinawanusin the Okinawa region, andC. costipennisin the Sakishima region. Their mtDNA sequences suggested that ancestralC. costipennispopulation was first separated between the Central and Southern Ryukyu areas, and the northern half was then subdivided betweenC. costipennisin the Amami andC. okinawanusin the Okinawa. The application of the molecular evolutionary clocks of coleopteran insects indicated that their vicariance occurred 1.0–1.4 million years ago, suggesting the influence of submergence and subdivision of a paleopeninsula extending between the Ryukyu Islands and continental China through Taiwan in the early Pleistocene.

scholarly journals A new early-branching armoured dinosaur from the Lower Jurassic of southwestern China

2021 ◽  
Author(s):  
Xi Yao ◽  
Paul Barrett ◽  
Lei Yang ◽  
Xing Xu ◽  
Shundong Bi
Keyword(s):  
Fossil Record ◽  
Evolutionary History ◽  
Yunnan Province ◽  
Morphological Diversity ◽  
Lower Jurassic ◽  
Early Jurassic ◽  
New Taxon ◽  
Unique Combination ◽  
Geographic Spread ◽  
History Of

The early evolutionary history of the armoured dinosaurs (Thyreophora) is obscured by its patchily distributed fossil record and by conflicting views on the relationships of its Early Jurassic representatives. Here, we describe an early-diverging thyreophoran from the Lower Jurassic Fengjiahe Formation of Yunnan Province, China, on the basis of an associated partial skeleton that includes skull, axial, limb and armour elements. It can be diagnosed as a new taxon based on numerous cranial and postcranial autapomorphies and is further distinguished from all other thyreophorans by a unique combination of character states. Although the robust postcranium is similar to that of more deeply nested ankylosaurs and stegosaurs, phylogenetic analysis recovers it as either the sister taxon of Emausaurus or of the clade Scelidosaurus and Eurypoda. This new taxon, Yuxisaurus kopchicki, represents the first valid thyreophoran dinosaur to be described from the Early Jurassic of Asia and confirms the rapid geographic spread and diversification of the clade after its first appearance in the Hettangian. Its heavy build and distinctive armour also hint at previously unrealised morphological diversity early in the clade history.

scholarly journals The complex evolution of the metazoan HSP70 gene family

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Er-meng Yu ◽  
Tatsuki Yoshinaga ◽  
Frank L. Jalufka ◽  
Hashimul Ehsan ◽  
David B. Mark Welch ◽  
...  
Keyword(s):  
Heat Shock ◽  
Molecular Chaperones ◽  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Evolutionary Relationship ◽  
Purifying Selection ◽  
Hsp70 Family ◽  
Number Of Genes ◽  
History Of ◽  
Species Specific

AbstractThe metazoan 70-kDa heat shock protein (HSP70) family contains several members localized in different subcellular compartments. The cytosolic members have been classified into inducible HSP70s and constitutive heat shock cognates (HSC70s), but their distinction and evolutionary relationship remain unclear because of occasional reports of “constitutive HSP70s” and the lack of cross-phylum comparisons. Here we provide novel insights into the evolution of these important molecular chaperones. Phylogenetic analyses of 125 full-length HSP70s from a broad range of phyla revealed an ancient duplication that gave rise to two lineages from which all metazoan cytosolic HSP70s descend. One lineage (A) contains a relatively small number of genes from many invertebrate phyla, none of which have been shown to be constitutively expressed (i.e., either inducible or unknown). The other lineage (B) included both inducible and constitutive genes from diverse phyla. Species-specific duplications are present in both lineages, and Lineage B contains well-supported phylum-specific clades for Platyhelminthes, Rotifera, Nematoda, Porifera/Cnidaria, and Chordata. Some genes in Lineage B have likely independently acquired inducibility, which may explain the sporadic distribution of “HSP70” or “HSC70” in previous phylogenetic analyses. Consistent with the diversification history within each group, inducible members show lower purifying selection pressure compared to constitutive members. These results illustrate the evolutionary history of the HSP70 family, encouraging us to propose a new nomenclature: “HSP70 + subcellular localization + linage + copy number in the organism + inducible or constitutive, if known.” e.g., HSP70cA1i for cytosolic Lineage A, copy 1, inducible.

New cyriacotheriid pantodonts (Mammalia, Pantodonta) from the Paleocene of Alberta, Canada, and the relationships of Cyriacotheriidae

2010 ◽  
Vol 84 (2) ◽  
pp. 197-215 ◽  
Author(s):  
Craig S. Scott
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Fossil Record ◽  
Evolutionary History ◽  
New Genus ◽  
The Family ◽  
Two New Species ◽  
Unusual Combination ◽  
Early Paleocene ◽  
History Of

Cyriacotheriidae are a family of unusual small-bodied pantodonts known from the Paleocene of the Western Interior of North America. Cyriacotheriids possess a suite of dental characters similar to that of pantodonts (e.g., molar dilambdodonty, lingual molar hypoconulids), as well as several divergent features (e.g., molarized premolars, strong molar conules) that have been interpreted as “dermopteran-like.” the unusual combination of pantodont and dermopteran-like characters, combined with a limited fossil record, has made attempts at understanding the broader relationships of Cyriacotheriidae difficult. This paper reports on a new genus and two new species of cyriacotheriids from the Paleocene of Alberta, Canada, with both species significantly older than those of the only previously described cyriacotheriid, Cyriacotherium. Collectively, the dentitions of these new taxa exhibit derived characters seen in Cyriacotherium (e.g., robust molar conules, strong molar dilambdodonty) in addition to a number of plesiomorphies seen in more basal pantodonts (e.g., conspicuous molar entoconids, deep premolar ectoflexus) and, importantly, posterior premolars that are weakly molariform and non-dilambdodont. A phylogenetic analysis of the new cyriacotheriid, basal pantodonts, dermopterans, and dermopteran-like eutherians resulted in Cyriacotheriidae nesting within a monophyletic Pantodonta. the results strengthen previous hypotheses regarding the pantodont affinities of the family, and suggest that the dermopteran-like features seen in the more derived Cyriacotherium were acquired convergently. Although the discovery of new cyriacotheriids sheds light on the evolutionary history of the family, it cannot resolve the ongoing questions of pantodont origins; nonetheless, their discovery in strata of early Paleocene age indicates that significant parts of the evolutionary history of Cyriacotheriidae, and North American pantodonts more generally, have yet to be discovered.

scholarly journals Hagfish from the Cretaceous Tethys Sea and a reconciliation of the morphological–molecular conflict in early vertebrate phylogeny

2019 ◽  
Vol 116 (6) ◽  
pp. 2146-2151 ◽  
Author(s):  
Tetsuto Miyashita ◽  
Michael I. Coates ◽  
Robert Farrar ◽  
Peter Larson ◽  
Phillip L. Manning ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Morphological Characters ◽  
Morphological Data ◽  
Vertebrate Lineage ◽  
Crown Group ◽  
Tethys Sea ◽  
History Of ◽  
Animal Phylogeny ◽  
Early Late

Hagfish depart so much from other fishes anatomically that they were sometimes considered not fully vertebrate. They may represent: (i) an anatomically primitive outgroup of vertebrates (the morphology-based craniate hypothesis); or (ii) an anatomically degenerate vertebrate lineage sister to lampreys (the molecular-based cyclostome hypothesis). This systematic conundrum has become a prominent case of conflict between morphology- and molecular-based phylogenies. To date, the fossil record has offered few insights to this long-branch problem or the evolutionary history of hagfish in general, because unequivocal fossil members of the group are unknown. Here, we report an unequivocal fossil hagfish from the early Late Cretaceous of Lebanon. The soft tissue anatomy includes key attributes of living hagfish: cartilages of barbels, postcranial position of branchial apparatus, and chemical traces of slime glands. This indicates that the suite of characters unique to living hagfish appeared well before Cretaceous times. This new hagfish prompted a reevaluation of morphological characters for interrelationships among jawless vertebrates. By addressing nonindependence of characters, our phylogenetic analyses recovered hagfish and lampreys in a clade of cyclostomes (congruent with the cyclostome hypothesis) using only morphological data. This new phylogeny places the fossil taxon within the hagfish crown group, and resolved other putative fossil cyclostomes to the stem of either hagfish or lamprey crown groups. These results potentially resolve the morphological–molecular conflict at the base of the Vertebrata. Thus, assessment of character nonindependence may help reconcile morphological and molecular inferences for other major discords in animal phylogeny.

Homoplasy and extinction: the phylogeny of cassidulid echinoids (Echinodermata)

2019 ◽  
Vol 187 (3) ◽  
pp. 622-660 ◽  
Author(s):  
Camilla Souto ◽  
Rich Mooi ◽  
Luciana Martins ◽  
Carla Menegola ◽  
Charles R Marshall
Keyword(s):  
Evolutionary History ◽  
Cladistic Analysis ◽  
Future Studies ◽  
Novel Traits ◽  
The Family ◽  
Phylogenetic Resolution ◽  
History Of ◽  
Recent Species ◽  
Taxonomic Implications ◽  
High Diversity

Abstract Inclusion of fossils can be crucial to address evolutionary questions, because their unique morphology, often drastically modified in recent species, can improve phylogenetic resolution. We performed a cladistic analysis of 45 cassidulids with 98 characters, which resulted in 24 most parsimonious trees. The strict consensus recovers three major cassiduloid clades, and the monophyly of the family Cassidulidae is not supported. Ancillary analyses to determine the sensitivity of the phylogeny to missing data do not result in significantly different topologies. The taxonomic implications of these results, including the description of a new cassiduloid family and the evolution of some morphological features, are discussed. Cassiduloids (as defined here) most probably originated in the Early Cretaceous, and their evolutionary history has been dominated by high levels of homoplasy and a dearth of unique, novel traits. Despite their high diversity during the Palaeogene, there are only seven extant cassiduloid species, and three of these are relicts of lineages dating back to the Eocene. Future studies of the biology of these poorly known species, some of which brood their young, will yield further insights into the evolutionary history of this group.

The genus Corvospongilla Annandale, 1911 (Porifera: Demospongiae: Spongillida) from Madagascar freshwater with description of a new species: biogeographic and evolutionary aspects

Zootaxa ◽  
2019 ◽  
Vol 4612 (4) ◽  
pp. 544
Author(s):  
RENATA MANCONI ◽  
ROBERTO PRONZATO
Keyword(s):  
New Species ◽  
Evolutionary History ◽  
First Record ◽  
Geographic Range ◽  
Disjunct Distribution ◽  
Unique Combination ◽  
Hydrographic Basin ◽  
History Of ◽  
Evolutionary Aspects ◽  
A New Species

We report here the first record of five genera of Spongillida (Porifera, Demospongiae) in both lentic and lotic water of Madagascar and the discovery of a new species of the genus Corvospongilla from the Betsiboka River hydrographic basin. Corvospongilla lemuriensis sp. n. diverges from all the other known species of the genus in its unique combination of diagnostic morphotraits (a) sessile gemmules with chambered pneumatic layer within tri-layered theca and enveloped by spicular cage of dominant acanthostrongyles, (b) dominant acanthostrongyles and less frequent acanthoxeas-strongyloxeas as megascleres and gemmuloscleres. The new species is characterised by the exclusive presence of a well-developed pneumatic layer in sessile gemmules not described for the genus until now. The new record confirms a Gondwanian track for the genus Corvospongilla and increases the knowledge on Spongillida historical biogeography. In synthesis the present discovery of Corvospongilla in the Malagasy biogeographic province (a) contributes to the assessment of Afrotropical biodiversity, (b) enlarges the geographic range of the genus reducing its disjunct distribution, and (c) focus on the evolutionary history of adaptive morphofunctional traits of resting bodies and life cycle timing in ephemeral water of the south-eastern Austral hemisphere. 

The first metriorhynchoid crocodyliform from the Aalenian (Middle Jurassic) of Germany, with implications for the evolution of Metriorhynchoidea

2019 ◽  
Author(s):  
Manuela Aiglstorfer ◽  
Philipe Havlik ◽  
Yanina Herrera
Keyword(s):  
Middle Jurassic ◽  
Evolutionary History ◽  
Marine Ecosystems ◽  
Morphological Features ◽  
New Taxon ◽  
Unique Combination ◽  
Southern Germany ◽  
Puzzle Piece ◽  
Character Distribution ◽  
History Of

Abstract Thalattosuchia, a clade of Mesozoic aquatic crocodyliforms, were the only archosaurs that ever became fully adapted to marine ecosystems. They are represented by two clades, the semiaquatic teleosauroids and the metriorhynchoids, which include fully pelagic forms. So far, little is known on the early evolutionary history of Metriorhynchoidea and data are sparse, especially from the early Middle Jurassic. Opisuchus meieri gen. et sp. nov. a metriorhynchoid crocodyliform from the early Aalenian (early Middle Jurassic) of southern Germany, is described here. It is one of the most complete specimens of a non-metriorhynchid metriorhynchoid, and the best-preserved thalattosuchian described from the Aalenian. The new taxon is represented by a nearly complete skull, which has a unique combination of characters distinguishing it from other species of Metriorhynchoidea. It displays a mosaic of plesiomorphic and apomorphic morphological features that sheds new light on early metriorhynchoid evolution. This taxon is an important puzzle piece, which will help to better track the mosaic character distribution in Thalattosuchia.

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