keyword
MENU ▼
Read by QxMD icon Read
search

Cetacea

keyword
https://www.readbyqxmd.com/read/29765678/a-new-large-squalodelphinid-cetacea-odontoceti-from-peru-sheds-light-on-the-early-miocene-platanistoid-disparity-and-ecology
#1
Giovanni Bianucci, Giulia Bosio, Elisa Malinverno, Christian de Muizon, Igor M Villa, Mario Urbina, Olivier Lambert
The South Asian river dolphin ( Platanista gangetica ) is the only extant survivor of the large clade Platanistoidea, having a well-diversified fossil record from the Late Oligocene to the Middle Miocene. Based on a partial skeleton collected from the Chilcatay Formation (Chilcatay Fm; southern coast of Peru), we report here a new squalodelphinid genus and species, Macrosqualodelphis ukupachai . A volcanic ash layer, sampled near the fossil, yielded the 40 Ar/39 Ar age of 18.78 ± 0.08 Ma (Burdigalian, Early Miocene)...
April 2018: Royal Society Open Science
https://www.readbyqxmd.com/read/29643269/signature-of-positive-selection-in-mitochondrial-dna-in-cetartiodactyla
#2
Satoko Mori, Masatoshi Matsunami
Acceleration of the amino acid substitution rate is a good indicator of positive selection in adaptive evolutionary changes of functional genes. Genomic information about mammals has become readily available in recent years, as many researchers have attempted to clarify the adaptive evolution of mammals by examining evolutionary rate change based on multiple loci. The order Cetartiodactyla (Artiodactyla and Cetacea) is one of the most diverse orders of mammals. Species in this order are found throughout all continents and seas, except Antarctica, and they exhibit wide variation in morphology and habitat...
April 10, 2018: Genes & Genetic Systems
https://www.readbyqxmd.com/read/29624668/evolution-of-cranial-telescoping-in-echolocating-whales-cetacea-odontoceti
#3
Morgan Churchill, Jonathan H Geisler, Brian L Beatty, Anjali Goswami
Odontocete (echolocating whale) skulls exhibit extreme posterior displacement and overlapping of facial bones, here referred to as retrograde cranial telescoping. To examine retrograde cranial telescoping across 40 million years of whale evolution, we collected 3D scans of whale skulls spanning odontocete evolution. We used a sliding semilandmark morphometric approach with Procrustes superimposition and PCA to capture and describe the morphological variation present in the facial region, followed by Ancestral Character State Reconstruction (ACSR) and evolutionary model fitting on significant components to determine how retrograde cranial telescoping evolved...
April 6, 2018: Evolution; International Journal of Organic Evolution
https://www.readbyqxmd.com/read/29581289/energetic-tradeoffs-control-the-size-distribution-of-aquatic-mammals
#4
William Gearty, Craig R McClain, Jonathan L Payne
Four extant lineages of mammals have invaded and diversified in the water: Sirenia, Cetacea, Pinnipedia, and Lutrinae. Most of these aquatic clades are larger bodied, on average, than their closest land-dwelling relatives, but the extent to which potential ecological, biomechanical, and physiological controls contributed to this pattern remains untested quantitatively. Here, we use previously published data on the body masses of 3,859 living and 2,999 fossil mammal species to examine the evolutionary trajectories of body size in aquatic mammals through both comparative phylogenetic analysis and examination of the fossil record...
March 26, 2018: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/29297306/de-novo-assembling-and-primary-analysis-of-genome-and-transcriptome-of-gray-whale-eschrichtius-robustus
#5
Alexey А Moskalev, Anna V Kudryavtseva, Alexander S Graphodatsky, Violetta R Beklemisheva, Natalya A Serdyukova, Konstantin V Krutovsky, Vadim V Sharov, Ivan V Kulakovskiy, Andrey S Lando, Artem S Kasianov, Dmitry A Kuzmin, Yuliya A Putintseva, Sergey I Feranchuk, Mikhail V Shaposhnikov, Vadim E Fraifeld, Dmitri Toren, Anastasia V Snezhkina, Vasily V Sitnik
BACKGROUND: Gray whale, Eschrichtius robustus (E. robustus), is a single member of the family Eschrichtiidae, which is considered to be the most primitive in the class Cetacea. Gray whale is often described as a "living fossil". It is adapted to extreme marine conditions and has a high life expectancy (77 years). The assembly of a gray whale genome and transcriptome will allow to carry out further studies of whale evolution, longevity, and resistance to extreme environment...
December 28, 2017: BMC Evolutionary Biology
https://www.readbyqxmd.com/read/29277542/evolution-of-the-mc5r-gene-in-placental-mammals-with-evidence-for-its-inactivation-in-multiple-lineages-that-lack-sebaceous-glands
#6
Mark S Springer, John Gatesy
MC5R is one of five melanocortin receptor genes found in placental mammals. MC5R plays an important role in energy homeostasis and is also expressed in the terminal differentiation of sebaceous glands. Among placental mammals there are multiple lineages that either lack or have degenerative sebaceous glands including Cetacea (whales, dolphins, and porpoises), Hippopotamidae (hippopotamuses), Sirenia (manatees and dugongs), Proboscidea (elephants), Rhinocerotidae (rhinos), and Heterocephalus glaber (naked mole rat)...
March 2018: Molecular Phylogenetics and Evolution
https://www.readbyqxmd.com/read/29189908/diffusion-tractography-reveals-pervasive-asymmetry-of-cerebral-white-matter-tracts-in-the-bottlenose-dolphin-tursiops-truncatus
#7
Alexandra K Wright, Rebecca J Theilmann, Sam H Ridgway, Miriam Scadeng
Brain enlargement is associated with concomitant growth of interneuronal distance, increased conduction time, and reduced neuronal interconnectivity. Recognition of these functional constraints led to the hypothesis that large-brained mammals should exhibit greater structural and functional brain lateralization. As a taxon with the largest brains in the animal kingdom, Cetacea provides a unique opportunity to examine asymmetries of brain structure and function. In the present study, diffusion tensor imaging and tractography were used to investigate cerebral white matter asymmetry in the bottlenose dolphin (Tursiops truncatus)...
November 30, 2017: Brain Structure & Function
https://www.readbyqxmd.com/read/29117197/new-records-of-the-dolphin-albertocetus-meffordorum-odontoceti-xenorophidae-from-the-lower-oligocene-of-south-carolina-encephalization-sensory-anatomy-postcranial-morphology-and-ontogeny-of-early-odontocetes
#8
Robert W Boessenecker, Erum Ahmed, Jonathan H Geisler
We report five new specimens of xenorophid dolphins from North and South Carolina. Four of the specimens represent the xenorophid Albertocetus meffordorum, previously only known from the holotype skull. The other is a fragmentary petrosal from the upper Oligocene Belgrade Formation that we refer to Echovenator sp, indicating at least two xenorophids from that unit. Two of the Albertocetus meffordorum specimens are from the lower Oligocene Ashley Formation: 1) a partial skeleton with neurocranium, fragmentary mandible, ribs, vertebrae, and chevrons, and 2) an isolated braincase...
2017: PloS One
https://www.readbyqxmd.com/read/29109917/-scaldiporia-vandokkumi-a-new-pontoporiid-mammalia-cetacea-odontoceti-from-the-late-miocene-to-earliest-pliocene-of-the-westerschelde-estuary-the-netherlands
#9
Klaas Post, Stephen Louwye, Olivier Lambert
Background: The family Pontoporiidae (Cetacea, Odontoceti, Inioidea) is currently represented in our oceans by just one species of diminutive dolphin ( Pontoporia blainvillei, franciscana). Although P. blainvillei is limited to coastal waters of the South Atlantic along Brazil, Uruguay and Argentina, multiple Miocene and Pliocene fossils indicate the past presence of members of the family in the South Atlantic, South Paciifc and North Atlantic oceans. Our comprehension of the origin and diversity of this clade and of the relationships of its members with other inioids is hampered by the fact that part of the described fossil specimens, especially from the North Atlantic realm, are cranial fragments often associated to limited stratigraphic information...
2017: PeerJ
https://www.readbyqxmd.com/read/29068152/review-and-experimental-evaluation-of-the-embryonic-development-and-evolutionary-history-of-flipper-development-and-hyperphalangy-in-dolphins-cetacea-mammalia
#10
Lisa Noelle Cooper, Karen E Sears, Brooke A Armfield, Bhavneet Kala, Merla Hubler, J G M Thewissen
Cetaceans are the only mammals to have evolved hyperphalangy, an increase in the number of phalanges beyond the mammalian plesiomorphic condition of three phalanges per digit. In this study, cetaceans were used as a novel model to review previous studies of mammalian hyperphalangy and contribute new experimental evidence as to the molecular origins of this phenotype in embryos of the pantropical spotted dolphin (Stenella attenuata). Results show embryos of dolphins, mice, and pigs share similar spatiotemporal patterns of signaling proteins known to shape limbs of mammals (e...
January 2018: Genesis: the Journal of Genetics and Development
https://www.readbyqxmd.com/read/28981559/description-of-the-karyotypes-of-stejneger-s-beaked-whale-mesoplodon-stejnegeri-and-hubbs-beaked-whale-m-carlhubbsi
#11
Nozomi Kurihara, Yuko Tajima, Tadasu K Yamada, Ayaka Matsuda, Takashi Matsuishi
The genus Mesoplodon (Cetacea: Odontoceti: Ziphiidae) is one of the few cetacean genera with the karyotype 2n = 42. The 2n = 42 karyotype of M. europaeus and M. carlhubbsi is largely consistent with the general cetacean karyotype 2n = 44, although other 2n = 42 karyotypes do not exhibit clear homologies with the general cetacean karyotype. Therefore, the chromosomes of Mesoplodon species may be the key to understanding cetacean karyological evolution. In the present study, the male karyotypes of M. stejnegeri and M...
October 2017: Genetics and Molecular Biology
https://www.readbyqxmd.com/read/28858207/x-chromosome-evolution-in-cetartiodactyla
#12
Anastasia A Proskuryakova, Anastasia I Kulemzina, Polina L Perelman, Alexey I Makunin, Denis M Larkin, Marta Farré, Anna V Kukekova, Jennifer Lynn Johnson, Natalya A Lemskaya, Violetta R Beklemisheva, Melody E Roelke-Parker, June Bellizzi, Oliver A Ryder, Stephen J O'Brien, Alexander S Graphodatsky
The phenomenon of a remarkable conservation of the X chromosome in eutherian mammals has been first described by Susumu Ohno in 1964. A notable exception is the cetartiodactyl X chromosome, which varies widely in morphology and G-banding pattern between species. It is hypothesized that this sex chromosome has undergone multiple rearrangements that changed the centromere position and the order of syntenic segments over the last 80 million years of Cetartiodactyla speciation. To investigate its evolution we have selected 26 evolutionarily conserved bacterial artificial chromosome (BAC) clones from the cattle CHORI-240 library evenly distributed along the cattle X chromosome...
August 31, 2017: Genes
https://www.readbyqxmd.com/read/28851538/unusual-loss-of-chymosin-in-mammalian-lineages-parallels-neo-natal-immune-transfer-strategies
#13
Mónica Lopes-Marques, Raquel Ruivo, Elza Fonseca, Ana Teixeira, L Filipe C Castro
Gene duplication and loss are powerful drivers of evolutionary change. The role of loss in phenotypic diversification is notably illustrated by the variable enzymatic repertoire involved in vertebrate protein digestion. Among these we find the pepsin family of aspartic proteinases, including chymosin (Cmy). Previous studies demonstrated that Cmy, a neo-natal digestive pepsin, is inactivated in some primates, including humans. This pseudogenization event was hypothesized to result from the acquisition of maternal immune immunoglobulin G (IgG) transfer...
November 2017: Molecular Phylogenetics and Evolution
https://www.readbyqxmd.com/read/28808552/evolution-of-mammalian-migrations-for-refuge-breeding-and-food
#14
Gitanjali E Gnanadesikan, William D Pearse, Allison K Shaw
Many organisms migrate between distinct habitats, exploiting variable resources while profoundly affecting ecosystem services, disease spread, and human welfare. However, the very characteristics that make migration captivating and significant also make it difficult to study, and we lack a comprehensive understanding of which species migrate and why. Here we show that, among mammals, migration is concentrated within Cetacea and Artiodactyla but also diffusely spread throughout the class (found in 12 of 27 orders)...
August 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28739936/gene-culture-coevolution-in-whales-and-dolphins
#15
Hal Whitehead
Whales and dolphins (Cetacea) have excellent social learning skills as well as a long and strong mother-calf bond. These features produce stable cultures, and, in some species, sympatric groups with different cultures. There is evidence and speculation that this cultural transmission of behavior has affected gene distributions. Culture seems to have driven killer whales into distinct ecotypes, which may be incipient species or subspecies. There are ecotype-specific signals of selection in functional genes that correspond to cultural foraging behavior and habitat use by the different ecotypes...
July 24, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28726248/finding-sacral-developmental-evolution-of-the-axial-skeleton-of-odontocetes-cetacea
#16
Emily A Buchholtz, Jessica K Gee
Axial morphology was dramatically transformed during the transition from terrestrial to aquatic environments by archaeocete cetaceans, and again during the subsequent odontocete radiation. Here, we reconstruct the sequence of developmental events that underlie these phenotypic transitions. Archaeocete innovations include the loss of primaxial/abaxial interaction at the sacral/pelvic articulation and the modular dissociation of the fluke from the remainder of the tail. Odontocetes subsequently integrated lumbar, sacral, and anterior caudal vertebrae into a single torso module, and underwent multiple series-specific changes in vertebral count...
July 2017: Evolution & Development
https://www.readbyqxmd.com/read/28573006/a-new-fossil-dolphin-dilophodelphis-fordycei-provides-insight-into-the-evolution-of-supraorbital-crests-in-platanistoidea-mammalia-cetacea
#17
Alexandra T Boersma, Matthew R McCurry, Nicholas D Pyenson
Many odontocete groups have developed enlarged facial crests, although these crests differ in topography, composition and function. The most elaborate crests occur in the South Asian river dolphin (Platanista gangetica), in which they rise dorsally as delicate, pneumatized wings anterior of the facial bones. Their position wrapping around the melon suggests their involvement in sound propagation for echolocation. To better understand the origin of crests in this lineage, we examined facial crests among fossil and living Platanistoidea, including a new taxon, Dilophodelphis fordycei, nov...
May 2017: Royal Society Open Science
https://www.readbyqxmd.com/read/28333389/the-cochlea-of-the-enigmatic-pygmy-right-whale-caperea-marginata-informs-mysticete-phylogeny
#18
Travis Park, Felix G Marx, Erich M G Fitzgerald, Alistair R Evans
The pygmy right whale, Caperea marginata, is the least understood extant baleen whale (Cetacea, Mysticeti). Knowledge on its basic anatomy, ecology, and fossil record is limited, even though its singular position outside both balaenids (right whales) and balaenopteroids (rorquals + grey whales) gives Caperea a pivotal role in mysticete evolution. Recent investigations of the cetacean cochlea have provided new insights into sensory capabilities and phylogeny. Here, we extend this advance to Caperea by describing, for the first time, the inner ear of this enigmatic species...
June 2017: Journal of Morphology
https://www.readbyqxmd.com/read/28293739/a-new-synthesium-species-digenea-brachycladiidae-from-the-bottlenose-dolphin-tursiops-truncatus-cetacea-delphinidae-in-southwestern-atlantic-waters
#19
Mariana B Ebert, Maria I Mülller, Juliana Marigo, Ana L S Valente, Marta J Cremer, Reinaldo J da Silva
A new species of Synthesium from the bottlenose dolphin Tursiops truncatus in South Brazilian waters is described. Morphological and molecular identification was performed, and phylogenetic analyses were carried out using the ribosomal small subunit and internal transcribed spacer 1 and the mitochondrial NDH dehydrogenase subunit 3 and cytochrome c oxidase subunit 1 genes. The main characteristics of the new species are the subterminal round-shaped oral sucker, the anterior distribution of vitellaria reaching the level of the ovary and the oval-shaped testes...
May 2017: Parasitology Research
https://www.readbyqxmd.com/read/28257606/morphology-and-ultrastructure-of-the-amazon-river-dolphin-inia-geoffrensis-spermatozoa
#20
Rodrigo S Amaral, Vera M F Da Silva, Fabíola X Valdez Domingos, Anthony R Martin
The spermatozoa from seven adult Amazon river dolphins (Inia geoffrensis, CETACEA: INIIDAE) were analyzed by light and electron microscopy. The spermatozoa showed an elongated ellipsoid shaped head and a long tail with a well distinguishable midpiece. The head spermatozoa have a smooth surface like other odontocetes examined, with the exception of the Delphinidae family. The mean dimensions of the spermatozoa were within the range already reported for other cetaceans. The spermatozoa midpiece, as in other cetaceans, showed a random pattern of mitochondria, different from that described for other mammals...
August 2017: Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology
keyword
keyword
53397
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"