New skeletal material of Andrewsiphius and Kutchicetus, two Eocene cetaceans from India

2009 ◽  
Vol 83 (5) ◽  
pp. 635-663 ◽  
Author(s):  
J. G. M. Thewissen ◽  
Sunil Bajpap
Keyword(s):  
Phylogenetic Analysis ◽  
Middle Eocene ◽  
Indian Subcontinent ◽  
Single Species ◽  
Phylogenetic Position ◽  
Mandibular Symphysis ◽  
Caudal Vertebrae ◽  
Skeletal Material ◽  
Independent Branch

The Eocene cetacean genera Andrewsiphius and Kutchicetus are systematically revised, their anatomy described, and their phylogenetic position analyzed. Each genus contains a single species, A. sloani and K minimus, and both are known only from the middle Eocene of the Indian Subcontinent. Andrewsiphius and Kutchicetus differ in a number of respects, the most important dental difference being that P2, P3, p2, and p3 are double-rooted in Andrewsiphius and single-rooted in Kutchicetus. Lower molars are separated by diastemata in Kutchicetus, but not in Andrewsiphius. Postcranially, Andrewsiphius has caudal vertebrae that are far more robust than those of Kutchicetus.We propose the new clade Andrewsiphiinae for these two genera, based on their unique characters: the extremely slender jaw, fused mandibular symphysis, narrow palate and rostrum, and lower molars that have a low crown with three cusps lined up rostro-caudally. A phylogenetic analysis indicates that andrewsiphiines are either a subfamily of Remingtonocetidae or an independent branch on the Eocene cetacean lineage. Interpreting conservatively, we classify them as remingtonocetids. Andrewsiphiines have a long, robust, dorso-ventrally flattened tail and short limbs, suggesting that they swam using dorsoventral undulation of the tail.

scholarly journals A new protocetid whale offers clues to biogeography and feeding ecology in early cetacean evolution

2021 ◽  
Vol 288 (1957) ◽  
pp. 20211368
Author(s):  
Abdullah S. Gohar ◽  
Mohammed S. Antar ◽  
Robert W. Boessenecker ◽  
Dalia A. Sabry ◽  
Sanaa El-Sayed ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Feeding Ecology ◽  
Middle Eocene ◽  
Mechanical Processing ◽  
Mandibular Symphysis ◽  
Feeding Style ◽  
Terrestrial Mammals ◽  
Partial Skeleton

Over about 10 million years, the ancestors of whales transformed from herbivorous, deer-like, terrestrial mammals into carnivorous and fully aquatic cetaceans. Protocetids are Eocene whales that represent a unique semiaquatic stage in that dramatic evolutionary transformation. Here, we report on a new medium-sized protocetid, Phiomicetus anubis gen. et sp. nov., consisting of a partial skeleton from the middle Eocene (Lutetian) of the Fayum Depression in Egypt. The new species differs from other protocetids in having large, elongated temporal fossae, anteriorly placed pterygoids, elongated parietals, an unfused mandibular symphysis that terminates at the level of P 3 , and a relatively enlarged I 3 . Unique features of the skull and mandible suggest a capacity for more efficient oral mechanical processing than the typical protocetid condition, thereby allowing for a strong raptorial feeding style. Phylogenetic analysis nests Phiomicetus within the paraphyletic Protocetidae, as the most basal protocetid known from Africa. Recovery of Phiomicetus from the same bed that yielded the remingtonocetid Rayanistes afer provides the first clear evidence for the co-occurrence of the basal cetacean families Remingtonocetidae and Protocetidae in Africa. The discovery of Phiomicetus further augments our understanding of the biogeography and feeding ecology of early whales.

scholarly journals A new large Pliosaurid from the Barremian (Lower Cretaceous) of Sáchica, Boyacá, Colombia

2018 ◽  
Vol 22 (4) ◽  
pp. 223-238 ◽  
Author(s):  
María Eurídice Páramo-Fonseca ◽  
Cristian David Benavides-Cabra ◽  
Ingry Esmirna Gutiérrez
Keyword(s):  
Lower Cretaceous ◽  
New Genus ◽  
Cervical Vertebrae ◽  
Cladistic Analysis ◽  
Morphological Characteristics ◽  
Phylogenetic Position ◽  
New Genus And Species ◽  
Mandibular Symphysis ◽  
Caudal Vertebrae ◽  
Mandibular Teeth

A new fossil MP111209-1 found in the Barremian beds of Sáchica, a town near Villa de Leiva representing the more complete skeleton found in the region is described here. After a detailed study of its morphological characteristics, it is evident that the new specimen represents a new genus and species of brachauchenine pliosaurid from Central Colombia that we named Sachicasaurus vitae gen. et sp. nov. Sachicasaurus is a large brachauchenine (almost 10 m in length) characterized by the following combination of characters: skull exceeding two meters in length,  transverse constriction in the rostrum, caniniform teeth present, pineal foramen in a very advanced position, palatines separated in the midline by the pterygoids, very short mandibular symphysis (bearing four teeth positions), reduced number of mandibular teeth (less than 20), slender hyoid bones, 12 cervical vertebrae, cervical centra showing ventral foramina, single rib facet in all cervical centra, at least 40 pre-caudal vertebrae, and ilium with a long posterior projection. Although it is difficult to clearly establish the phylogenetic position of Sachicasaurus viate within Brachaucheninae due to its combination of primitive and derived features, the morphological comparisons and the cladistic analysis show an evident phylogenetic proximity of Sachicasaurus to the Aptian-Albian genus Kronosaurus.

scholarly journals A little frog leaps a long way: compounded colonizations of the Indian Subcontinent discovered in the tiny Oriental frog genus Microhyla (Amphibia: Microhylidae)

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9411 ◽  
Author(s):  
Vladislav A. Gorin ◽  
Evgeniya N. Solovyeva ◽  
Mahmudul Hasan ◽  
Hisanori Okamiya ◽  
D.M.S. Suranjan Karunarathna ◽  
...  
Keyword(s):  
Body Size ◽  
Middle Eocene ◽  
Morphological Evolution ◽  
Indian Subcontinent ◽  
Phylogenetic Analyses ◽  
Species Group ◽  
Indian Plate ◽  
Phylogenetic Position ◽  
Seasonally Dry ◽  
Species Groups

Frogs of the genus Microhyla include some of the world’s smallest amphibians and represent the largest radiation of Asian microhylids, currently encompassing 50 species, distributed across the Oriental biogeographic region. The genus Microhyla remains one of the taxonomically most challenging groups of Asian frogs and was found to be paraphyletic with respect to large-sized fossorial Glyphoglossus. In this study we present a time-calibrated phylogeny for frogs in the genus Microhyla, and discuss taxonomy, historical biogeography, and morphological evolution of these frogs. Our updated phylogeny of the genus with nearly complete taxon sampling includes 48 nominal Microhyla species and several undescribed candidate species. Phylogenetic analyses of 3,207 bp of combined mtDNA and nuDNA data recovered three well-supported groups: the Glyphoglossus clade, Southeast Asian Microhyla II clade (includes M. annectens species group), and a diverse Microhyla I clade including all other species. Within the largest major clade of Microhyla are seven well-supported subclades that we identify as the M. achatina, M. fissipes, M. berdmorei, M. superciliaris, M. ornata, M. butleri, and M. palmipes species groups. The phylogenetic position of 12 poorly known Microhyla species is clarified for the first time. These phylogenetic results, along with molecular clock and ancestral area analyses, show the Microhyla—Glyphoglossus assemblage to have originated in Southeast Asia in the middle Eocene just after the first hypothesized land connections between the Indian Plate and the Asian mainland. While Glyphoglossus and Microhyla II remained within their ancestral ranges, Microhyla I expanded its distribution generally east to west, colonizing and diversifying through the Cenozoic. The Indian Subcontinent was colonized by members of five Microhyla species groups independently, starting with the end Oligocene—early Miocene that coincides with an onset of seasonally dry climates in South Asia. Body size evolution modeling suggests that four groups of Microhyla have independently achieved extreme miniaturization with adult body size below 15 mm. Three of the five smallest Microhyla species are obligate phytotelm-breeders and we argue that their peculiar reproductive biology may be a factor involved in miniaturization. Body size increases in Microhyla—Glyphoglossus seem to be associated with a burrowing adaptation to seasonally dry habitats. Species delimitation analyses suggest a vast underestimation of species richness and diversity in Microhyla and reveal 15–33 undescribed species. We revalidate M. nepenthicola, synonymize M. pulverata with M. marmorata, and provide insights on taxonomic statuses of a number of poorly known species. Further integrative studies, combining evidence from phylogeny, morphology, advertisement calls, and behavior will result in a better systematic understanding of this morphologically cryptic radiation of Asian frogs.

scholarly journals The new Internal Transcribed Spacer 2 diagnostic tool clarifies the taxonomic position and geographic distribution of the North American malaria vector Anopheles punctipennis

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
James M. Hodge ◽  
Andrey A. Yurchenko ◽  
Dmitriy A. Karagodin ◽  
Reem A. Masri ◽  
Ryan C. Smith ◽  
...  
Keyword(s):  
Malaria Vector ◽  
Internal Transcribed Spacer ◽  
Single Species ◽  
Its2 Sequence ◽  
Pathogen Transmission ◽  
Molecular Diagnostic ◽  
Diagnostic Tools ◽  
Sequence Length ◽  
Phylogenetic Position ◽  
Internal Transcribed Spacer 2

Abstract Background The malaria mosquito Anopheles punctipennis, a widely distributed species in North America, is capable of transmitting human malaria and is actively involved in the transmission of the ungulate malaria parasite Plasmodium odocoilei. However, molecular diagnostic tools based on Internal Transcribed Spacer 2 (ITS2) of ribosomal DNA are lacking for this species. Anopheles punctipennis is a former member of the Anopheles maculipennis complex but its systematic position remains unclear. Methods In this study, ITS2 sequences were obtained from 276 An. punctipennis specimens collected in the eastern and midwestern United States and a simple and robust Restriction Fragment Length Polymorphism approach for species identification was developed. The maximum-likelihood phylogenetic tree was constructed based on ITS2 sequences available through this study and from GenBank for 20 species of Anopheles. Results The analysis demonstrated a consistent ITS2 sequence length and showed no indications of intragenomic variation among the samples based on ITS2, suggesting that An. punctipennis represents a single species in the studied geographic locations. In this study, An. punctipennis was found in urban, rural, and forest settings, suggesting its potential broad role in pathogen transmission. Phylogeny based on ITS2 sequence comparison demonstrated the close relationship of this species with other members of the Maculipennis group. Conclusions This study developed molecular tools based on ITS2 sequences for the malaria vector An. punctipennis and clarified the phylogenetic position of the species within the Maculipennis group.

scholarly journals Whole-Body Regeneration in Sponges: Diversity, Fine Mechanisms, and Future Prospects

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 506
Author(s):  
Alexander Ereskovsky ◽  
Ilya E. Borisenko ◽  
Fyodor V. Bolshakov ◽  
Andrey I. Lavrov
Keyword(s):  
Single Species ◽  
Whole Body ◽  
Phylogenetic Position ◽  
Main Body ◽  
Regenerative Processes ◽  
Cellular Mechanisms ◽  
Different Types ◽  
Dissociated Cells ◽  
Shed Light ◽  
Regeneration Processes

While virtually all animals show certain abilities for regeneration after an injury, these abilities vary greatly among metazoans. Porifera (Sponges) is basal metazoans characterized by a wide variety of different regenerative processes, including whole-body regeneration (WBR). Considering phylogenetic position and unique body organization, sponges are highly promising models, as they can shed light on the origin and early evolution of regeneration in general and WBR in particular. The present review summarizes available data on the morphogenetic and cellular mechanisms accompanying different types of WBR in sponges. Sponges show a high diversity of WBR, which principally could be divided into (1) WBR from a body fragment and (2) WBR by aggregation of dissociated cells. Sponges belonging to different phylogenetic clades and even to different species and/or differing in the anatomical structure undergo different morphogeneses after similar operations. A common characteristic feature of WBR in sponges is the instability of the main body axis: a change of the organism polarity is described during all types of WBR. The cellular mechanisms of WBR are different across sponge classes, while cell dedifferentiations and transdifferentiations are involved in regeneration processes in all sponges. Data considering molecular regulation of WBR in sponges are extremely scarce. However, the possibility to achieve various types of WBR ensured by common morphogenetic and cellular basis in a single species makes sponges highly accessible for future comprehensive physiological, biochemical, and molecular studies of regeneration processes.

Tail length evolution in deer mice: linking morphology, behavior and function

2021 ◽  
Author(s):  
Emily R Hager ◽  
Hopi E Hoekstra
Keyword(s):  
Computational Models ◽  
Deer Mouse ◽  
Center Of Mass ◽  
Tail Length ◽  
Single Species ◽  
Deer Mice ◽  
Length Variation ◽  
Caudal Vertebrae ◽  
Long Tails ◽  
And Function

Abstract Determining how variation in morphology affects animal performance (and ultimately fitness) is key to understanding the complete process of evolutionary adaptation. Long tails have evolved many times in arboreal and semi-arboreal rodents; in deer mice, long tails have evolved repeatedly in populations occupying forested habit even within a single species (Peromyscus maniculatus). Here we use a combination of functional modeling, laboratory studies, and museum records to test hypotheses about the function of tail-length variation in deer mice. First, we use computational models, informed by museum records documenting natural variation in tail length, to test whether differences in tail morphology between forest and prairie subspecies can influence performance in behavioral contexts relevant for tail use. We find that the deer mouse tail plays little role in statically adjusting center of mass or in correcting body pitch and yaw, but rather it can affect body roll during arboreal locomotion. In this context, we find that even intraspecific tail-length variation could result in substantial differences in how much body rotation results from equivalent tail motions (i.e., tail effectiveness), but the relationship between commonly-used metrics of tail-length variation and effectiveness is non-linear. We further test whether caudal vertebra length, number, and shape are associated with differences in how much the tail can bend to curve around narrow substrates (i.e., tail curvature) and find that, as predicted, the shape of the caudal vertebrae is associated with intervertebral bending angle across taxa. However, although forest and prairie mice typically differ in both the length and number of caudal vertebrae, we do not find evidence that this pattern is the result of a functional trade-off related to tail curvature. Together, these results highlight how even simple models can both generate and exclude hypotheses about the functional consequences of trait variation for organismal-level performance.

The enigmatic diapsid Acerosodontosaurus piveteaui (Reptilia: Neodiapsida) from the Upper Permian of Madagascar and the paraphyly of “younginiform” reptiles

2009 ◽  
Vol 46 (9) ◽  
pp. 651-661 ◽  
Author(s):  
Constanze Bickelmann ◽  
Johannes Müller ◽  
Robert R. Reisz
Keyword(s):  
Phylogenetic Analysis ◽  
Data Matrix ◽  
Upper Permian ◽  
Phylogenetic Position ◽  
Ancestral Condition ◽  
Phylogenetic Data ◽  
First Time ◽  
Evolutionary Lineages

A restudy of the Upper Permian diapsid Acerosodontosaurus piveteaui from Madagascar indicates that the bone formerly identified as the quadratojugal is a fragment of a rib. This in turn implies that, in contrast to previous studies, the lower temporal arcade must be considered incomplete and derived relative to the ancestral condition. Since the phylogenetic position of Acerosodontosaurus is poorly understood, the taxon was entered into a modified phylogenetic data matrix of diapsid reptiles, and the purported monophyly of “Younginiformes” was tested for the first time by including all potential members of the clade as separate taxa, as well as other taxa from the same deposits. The results of the phylogenetic analysis do not support the monophyly of “younginiform” reptiles. Instead, most taxa cluster unresolved at the base of Neodiapsida, a finding that has important implications for the understanding of early diapsid evolution because it suggests that early neodiapsids represent several distinct evolutionary lineages. Acerosodontosaurus and Hovasaurus do form a clade, a finding consistent with the stratigraphic age and biogeography of these taxa.

scholarly journals Additional records and stratigraphic distribution of the middle Eocene carettochelyid turtle Anosteira pulchra from the Uinta Formation of Utah, North America

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9775
Author(s):  
Brent Adrian ◽  
Patricia A. Holroyd ◽  
J. Howard Hutchison ◽  
KE Beth Townsend
Keyword(s):  
North America ◽  
New Records ◽  
Middle Eocene ◽  
Single Species ◽  
Uinta Basin ◽  
Stratigraphic Framework ◽  
Multiple Levels ◽  
Land Mammal ◽  
Anatomical Information ◽  
Insight Into

Background Anosteira pulchra is one of two species of the obligately-aquatic freshwater clade Carettochelyidae (pig-nosed turtles) from the Eocene of North America. Anosteira pulchra is typically rare in collections, and their distribution is poorly documented. The Uinta Formation [Fm.] contains a diverse assemblage of turtles from the Uintan North American Land Mammal Age. Whereas turtles are abundantly preserved in the Uinta Fm., A. pulchra has been reported only from a few specimens in the Uinta C Member. Methods We describe new records of Anosteira pulchra from the Uinta Basin and analyze the distribution of 95 specimens from multiple repositories in the previously published stratigraphic framework of the middle and upper Uinta Fm. Results Here we report the first records of the species from the Uinta B interval, document it from multiple levels within the stratigraphic section and examine its uncommon appearance in only approximately 5% of localities where turtles have been systematically collected. This study details and extends the range of A. pulchra in the Uinta Fm. and demonstrates the presence of the taxon in significantly lower stratigraphic layers. These newly described fossils include previously unknown elements and associated trace fossils, with new anatomical information presented. This study provides insight into the taxonomy of Anosteira spp. in the middle Eocene, and suggests the presence of a single species, though no synonymy is defined here due to limits in Bridger material.

scholarly journals Asgard archaea are diverse, ubiquitous, and transcriptionally active microbes

2018 ◽  
Author(s):  
Mingwei Cai ◽  
Yang Liu ◽  
Zhichao Zhou ◽  
Yuchun Yang ◽  
Jie Pan ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Genomic Analysis ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Group D ◽  
Origin Of Eukaryotes

AbstractAsgard is a newly proposed archaeal superphylum. Phylogenetic position of Asgard archaea and its relationships to the origin of eukaryotes is attracting increasingly research interest. However, in-depth knowledge of their diversity, distribution, and activity of Asgard archaea remains limited. Here, we used phylogenetic analysis to cluster the publicly available Asgard archaeal 16S rRNA gene sequences into 13 subgroups, including five previously unknown subgroups. These lineages were widely distributed in anaerobic environments, with the majority of 16S rRNA gene sequences (92%) originating from sediment habitats. Co-occurrence analysis revealed potential relationships between Asgard, Bathyarchaeota, and Marine Benthic Group D archaea. Genomic analysis suggested that Asgard archaea are potentially mixotrophic microbes with divergent metabolic capabilities. Importantly, metatranscriptomics confirmed the versatile lifestyles of Lokiarchaeota and Thorarchaeota, which can fix CO2using the tetrahydromethanopterin Wood-Ljungdahl pathway, perform acetogenesis, and degrade organic matters. Overall, this study broadens the understandings of Asgard archaea ecology, and also provides the first evidence to support a transcriptionally active mixotrophic lifestyle of Asgard archaea, shedding light on the potential roles of these microorganisms in the global biogeochemical cycling.

First remingtonocetid archaeocete (Mammalia, Cetacea) from the middle Eocene of Egypt with implications for biogeography and locomotion in early cetacean evolution

2015 ◽  
Vol 89 (5) ◽  
pp. 882-893 ◽  
Author(s):  
Ryan M. Bebej ◽  
Iyad S. Zalmout ◽  
Ahmed A. Abed El-Aziz ◽  
Mohammed Sameh M. Antar ◽  
Philip D. Gingerich
Keyword(s):  
Middle Eocene ◽  
Lumbar Vertebrae ◽  
The Body ◽  
Power Stroke ◽  
Tethys Sea ◽  
Vertebral Centra ◽  
Hind Limbs ◽  
Caudal Vertebrae ◽  
Southern Tethys

AbstractRemingtonocetidae are Eocene archaeocetes that represent a unique experiment in cetacean evolution. They possess long narrow skulls, long necks, fused sacra, and robust hind limbs. Previously described remingtonocetids are known from middle Eocene Lutetian strata in Pakistan and India. Here we describe a new remingtonocetid, Rayanistes afer, n. gen. n. sp., recovered from a middle to late Lutetian interval of the Midawara Formation in Egypt. The holotype preserves a sacrum with four vertebral centra; several lumbar and caudal vertebrae; an innominate with a complete ilium, ischium, and acetabulum; and a nearly complete femur. The ilium and ischium of Rayanistes are bladelike, rising sharply from the body of the innominate anterior and posterior to the acetabulum, and the acetabular notch is narrow. These features are diagnostic of Remingtonocetidae, but their development also shows that Rayanistes had a specialized mode of locomotion. The expanded ischium is larger than that of any other archaeocete, supporting musculature for powerful retraction of the hind limbs during swimming. Posteriorly angled neural spines on lumbar vertebrae and other features indicate increased passive flexibility of the lumbus. Rayanistes probably used its enhanced lumbar flexibility to increase the length of the power stroke during pelvic paddling. Recovery of a remingtonocetid in Egypt broadens the distribution of Remingtonocetidae and shows that protocetids were not the only semiaquatic archaeocetes capable of dispersal across the southern Tethys Sea.

Sign in / Sign up

Export Citation Format

Share Document