scholarly journals Amniotic diversity of Taranga Hill-forest, Gujarat, India

Our Nature ◽  
1970 ◽  
Vol 8 (1) ◽  
pp. 144-156 ◽  
Author(s):  
C.D. Patel ◽  
M.I. Patel
Keyword(s):  
Evolutionary History ◽  
Food Sources ◽  
Arid Climate ◽  
Low Diversity ◽  
History Of ◽  
Semi Arid ◽  
High Diversity

Amniotes is the group of the animals’ viz., reptiles, birds and mammals, in which extra-embryonic membranes are developed around the embryo for different functions. Amniotic diversity of Taranga Hill-forest (THf) has been studied. THf was represented by 147 species belonging to 116 genera and 62 families. Of these, 24 species were reptiles (belonging 21 genus and 11 families), 98 species were birds (belonging 73 genus and 35 families) and 25 species were mammals (belonging 22 genus and 16 families). It shows that THf has good amniotic diversity. The THf covers 21.21% amniotic diversity of Gujarat and 7.07% of India. The total amniotic diversity of THf was covered by 66.67% species of birds, 17.01% species of mammals and 16.33% species of reptiles. Of the total 62 families, 6 families have high diversity, 18 families have moderate diversity, 10 families have low diversity and 28 families have very low diversity. The high-diversified six families were Colubridae, Accipitridae, Corvidae, Muscicapidae, Sylviidae and Passeridae. Diversity in an area is dependent upon the availability of variable food sources, habitats for roosting, resting, breeding and sheltering; semi-arid climate and evolutionary history of the Aravalli ranges.DOI: 10.3126/on.v8i1.4322

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 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.

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.

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.

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.

Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux
Keyword(s):  
Decision Making ◽  
Individual Differences ◽  
Cognitive Processes ◽  
Evolutionary History ◽  
Behavioral Responses ◽  
History Of ◽  
Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

Recent Rapid Climate Changes in Antarctic and their Influence on Low Diversity Ecosystems

2010 ◽  
Vol 17 (1) ◽  
pp. 17-30 ◽  
Author(s):  
Katarzyna J. Chwedorzewska
Keyword(s):  
Environmental Variables ◽  
Climate Changes ◽  
Biological Significance ◽  
Global Changes ◽  
Factors Affecting ◽  
Low Diversity ◽  
Main Factors ◽  
The Antarctic ◽  
High Diversity ◽  
Temperature Water

ABSTRACTThe geographic position, astronomic factors (e.g. the Earth’s maximum distance from the Sun during winter), ice cover and altitude are the main factors affecting the climate of the Antarctic, which is the coldest place on Earth. Parts of Antarctica are facing the most rapid rates of anthropogenic climate change currently seen on the planet. Climate changes are occurring throughout Antarctica, affecting three major groups of environmental variables of considerable biological significance: temperature, water, UV-B radiation.Low diversity ecosystems are expected to be more vulnerable to global changes than high diversity ecosystems

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