Relevant bibliographies by topics / Primitive mammal

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Primitive mammal'

Author: Grafiati
Published: 4 June 2021
Last updated: 8 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Primitive mammal.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Primitive mammal"

1

Dellovade, Tammy L., Jean-Pierre Hardelin, Nadia Soussi-Yanicostas, Donald W. Pfaff, Marlene Schwanzel-Fukuda, and Christine Petit. "Anosmin-1 immunoreactivity during embryogenesis in a primitive eutherian mammal." Developmental Brain Research 140, no. 2 (2003): 157–67. http://dx.doi.org/10.1016/s0165-3806(02)00544-8.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Cifelli, R. L. "A Primitive Higher Mammal from the Late Cretaceous of Southern Utah." Journal of Mammalogy 71, no. 3 (1990): 343–50. http://dx.doi.org/10.2307/1381944.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Cifelli, Richard L., and Christian De Muizon. "Marsupial mammal from the Upper Cretaceous North Horn Formation, Central Utah." Journal of Paleontology 72, no. 3 (1998): 532–37. http://dx.doi.org/10.1017/s0022336000024306.

Full text
Abstract:
Little is known of the non-dinosaurian fauna from the Cretaceous (Maastrichtian) part of the North Horn Formation, despite its biogeographic importance. Herein we describe a new marsupial mammal from the unit, founded on an exceptionally complete specimen of a juvenile individual, and present new information on the incisor region of early marsupials, based on comparison with complete specimens from the early Paleocene of Bolivia. Alphadon eatoni, new species, is the smallest Lancian species of the genus, and departs from a presumed marsupial morphotype in having the second lower incisor enlarged. The species is, however, primitive in lacking a “staggered” pattern to the incisor series and in having a labial mandibular foramen, and in these respects it differs from Paleocene and later marsupials. Poor representation of other taxa precludes meaningful comparison to most other North American Cretaceous marsupials, although Eodelphis, thought to be distantly related, also has an enlarged i2. Although Alphadon is characterized by many primitive features, the relative development of the incisors is not what would be predicted in a morphological antecedent to later Marsupialia.
APA, Harvard, Vancouver, ISO, and other styles
4

He, Jing, M. David Irwin, and YaPing Zhang. "Motilin and ghrelin gene experienced episodic evolution during primitive placental mammal evolution." Science China Life Sciences 53, no. 6 (2010): 677–82. http://dx.doi.org/10.1007/s11427-010-3105-6.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Li, Jinling, Yuan Wang, Yuanqing Wang, and Chuankui Li. "A new family of primitive mammal from the Mesozoic of western Liaoning, China." Chinese Science Bulletin 46, no. 9 (2001): 782–85. http://dx.doi.org/10.1007/bf03187223.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

GHEERBRANT, EMMANUEL, MOHAMED IAROCHENE, MBAREK AMAGHZAZ, and BAÂDI BOUYA. "Early African hyaenodontid mammals and their bearing on the origin of the Creodonta." Geological Magazine 143, no. 4 (2006): 475–89. http://dx.doi.org/10.1017/s0016756806002032.

Full text
Abstract:
We report a new proviverrine hyaenodontid creodont mammal, Boualitomus marocanensis, n.g., n.sp., from the earliest Eocene of Morocco, and provide new comments on Tinerhodon from the late Paleocene of Morocco. Aside from the autapomorphic loss of P/1, Boualitomus is characterized by a primitive morphology (e.g. M/3 subequal to M/2, short molar trigonid, narrow talonid, metaconid comparable to paraconid) which resembles most closely the proviverrine Prototomus. Boualitomus is more primitive than Prototomus, especially in its small size and the talonid of P/4 not being fully simplified, bearing at least two accessory cusps including a bulbous protostylid. These primitive features are remarkably reminiscent of Tinerhodon. The morphological relationship of Boualitomus and Tinerhodon supports the proviverrine affinity of the latter. Significant basal hyaenodontid synapomorphies of Boualitomus and Tinerhodon are the paraconid and paracristid development in M/1–3, anterior premolar morphology and occurrence of diastemata. Boualitomus and Tinerhodon throw new light upon the question of the origin of the Creodonta. Tinerhodon further fills the structural gap between Hyaenodontidae and primitive insectivore-like eutherians, and it provides additional data for the hypothesis of a didelphodontan origin for the Creodonta. The presence of cimolestids (as the stem-group of hyaenodontids) in the late Paleocene of Morocco, and the identification of Boualitomus and Tinerhodon as the most primitive and earliest known Hyaenodontidae, support an African origin of the family and its order.
APA, Harvard, Vancouver, ISO, and other styles
7

Jones, Matthew F., Qiang Li, Xijun Ni, and K. Christopher Beard. "The earliest Asian bats (Mammalia: Chiroptera) address major gaps in bat evolution." Biology Letters 17, no. 6 (2021): 20210185. http://dx.doi.org/10.1098/rsbl.2021.0185.

Full text
Abstract:
Bats dispersed widely after evolving the capacity for powered flight, and fossil bats are known from the early Eocene of most continents. Until now, however, bats have been conspicuously absent from the early Eocene of mainland Asia. Here, we report two teeth from the Junggar Basin of northern Xinjiang, China belonging to the first known early Eocene bats from Asia, representing arguably the most plesiomorphic bat molars currently recognized. These teeth combine certain bat synapomorphies with primitive traits found in other placental mammals, thereby potentially illuminating dental evolution among stem bats. The Junggar Basin teeth suggest that the dentition of the stem chiropteran family Onychonycteridae is surprisingly derived, although their postcranial anatomy is more primitive than that of any other Eocene bats. Additional comparisons with stem bat families Icaronycteridae and Archaeonycteridae fail to identify unambiguous synapomorphies for the latter taxa, raising the possibility that neither is monophyletic as currently recognized. The presence of highly plesiomorphic bats in the early Eocene of central Asia suggests that this region was an important locus for the earliest, transitional phases of bat evolution, as has been demonstrated for other placental mammal orders including Lagomorpha and Rodentia.
APA, Harvard, Vancouver, ISO, and other styles
8

Gheerbrant, Emmanuel, and Humberto Astibia. "Addition to the Late Cretaceous Laño mammal faunule (Spain) and to the knowledge of European “Zhelestidae” (Lainodontinae nov.)." Bulletin de la Société Géologique de France 183, no. 6 (2012): 537–46. http://dx.doi.org/10.2113/gssgfbull.183.6.537.

Full text
Abstract:
Abstract New mammal material from the Campano-Maastrichtian locality of Laño, Spanish Basque Country documents two new zhelestid eutherian species referred to the genus Lainodon. This material enlightens the upper molar pattern of the European zhelestids and confirms their originality and homogeneity. The European zhelestids are included in the new subfamily Lainodontinae, which is distinct and characterized by a mosaic of primitive and specialized features. The Lainodontinae clade adds to other endemic vertebrate taxa (among multituberculates, flightless birds, dinosaurs, and turtles) that typify the Late Cretaceous fauna of the European Archipelago. The material from Laño provides further evidence of a modest but significant lainodontine radiation known by five or six species belonging to two or three genera (Lainodon, Labes, ? Valentinella), which is currently restricted to western Europe, i.e. to the Ibero-Armorican Island. The plesiomorph features of the Lainodontinae (lower molar trigonid poorly compressed, upper molar without lingual cingulum) recall the earliest known zhelestids, and suggest an Asian origin from a Sheikhdzheilia-like stem lineage at the beginning of the Late Cretaceous. This dispersal event from Asia probably involved other vertebrate taxa, such as the multituberculate stem group of the kogaionid mammals and the hadrosaurid dinosaurs. The zhelestid subfamily Lainodontinae represents the most diverse and dominant taxon in the western European Late Cretaceous mammal fauna, which is eutherian-dominated, by contrast to the eastern European Late Cretaceous mammal fauna which is dominated by an original and at that time exclusive radiation of kogaionid multituberculates.
APA, Harvard, Vancouver, ISO, and other styles
9

Court, Nicholas, and Mohamed Mahboubi. "Reassessment of Lower Eocene Seggeurius amourensis: aspects of primitive dental morphology in the mammalian order Hyracoidea." Journal of Paleontology 67, no. 5 (1993): 889–93. http://dx.doi.org/10.1017/s002233600003715x.

Full text
Abstract:
New lower dental material of the fossil hyracoid mammal, Seggeurius amourensis Crochet, 1986, from Eocene deposits of the Southern Atlas in Algeria, has prompted a reevaluation of the genus. The dentition as a whole is first described in detail, thus providing a more precise characterization of the genus than has hitherto been available. Peculiarities, particularly in upper molar morphology, are sufficient to uphold a generic distinction. However, based largely on lower molar morphology Seggeurius amourensis is transferred from the subfamily Geniohyinae to Saghatheriinae. In the upper molars, absence of a postmetacrista and the presence of a preprotocrista continuous with the parastyle are interpreted as primitive features in hyracoids. In the lower molars, extreme reduction of the paracristid and the presence of a mesoconid are also considered primitive for hyracoids. These features together with small size, bunodonty, low crown height, and very simple premolar morphology indicate that Seggeurius amourensis is the most primitive hyrax yet recovered.
APA, Harvard, Vancouver, ISO, and other styles
10

Abarca-Buis, RenéFernando, María Elena Contreras-Figueroa, David Garciadiego-Cázares, and Edgar Krötzsch. "Control of fibrosis by TGFβ signalling modulation promotes redifferentiation during limited regeneration of mouse ear." International Journal of Developmental Biology 64, no. 7-8-9 (2020): 423–32. http://dx.doi.org/10.1387/ijdb.190237ra.

Full text
Abstract:
Transforming growth factor beta (TGFβ) signalling is involved in several aspects of regeneration in many organs and tissues of primitive vertebrates. It has been difficult to recognize the role of this signal in mammal regeneration due to the low ability of this animal class to reconstitute tissues. Nevertheless, ear-holes in middle-age female mice represent a model to study the limited epimorphic-like regeneration in mammals. Using this model, in this study we explored the possible participation of TGFβ signalling in mammal regeneration. Positive pSmad3 cells, as well as TGFβ1 and TGFβ3 isoforms, were detected during the redifferentiation phase in the blastema-like structure. Daily administration of the inhibitor of the TGFβ intracellular pathway, SB431542, during 7 days from the re-differentiation phase, resulted in a decreased level of pSmad3 accompanied by a transitory higher growth of the new tissue, larger cartilage nodules, and new muscle formation. These phenotypes were associated with a decrease in the number of α-SMA-positive cells and loose packing of collagen I. These results indicate that the modulation of the fibrosis mediated by TGFβ signalling contributes to enhancing the differentiation of cartilage and muscle during limited ear-hole regeneration.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Primitive mammal"

1

Bronnert, Constance. "Origine et premières dichotomies des Périssodactyles (Mammalia, Laurasiatheria) : apport des faunes de l'Éocène inférieur du bassin de Paris A primitive perissodactyl (Mammalia) from the early Eocene of Le Quesnoy (MP7, France) First European ‘Isectolophidae’ (Mammalia, Perissodactyla): Chowliia europea, sp. nov., from the lower Eocene of Le Quesnoy, France." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS563.

Full text
Abstract:
Les périssodactyles (comprenant aujourd’hui les chevaux, les rhinocéros et les tapirs) apparaissent au début de l’Éocène et se dispersent rapidement dans tout l’hémisphère Nord. Leur origine géographique, probablement asiatique, ainsi que leur origine phylogénétique est actuellement débattue. Ce travail présente une étude et une révision des périssodactyles hippomorphes de l’Éocène inférieur (MP7-MP10) d’Europe, ainsi qu’une nouvelle phylogénie pour tenter de répondre à ces questions. La majorité du matériel est inédite et provient du bassin de Paris, ainsi que du sud de la France. Douze espèces d’hippomorphes, dont deux nouvelles, et une nouvelle espèce d’isectolophidé ont été identifiés dans l’Éocène inférieur d’Europe. Les faunes rapprochés du MP7 présentent des différences entre le nord et le sud de l’Europe, confirmant l’hypothèse d’une barrière climatique. Un renouvellement des périssodactyles au niveau générique s’effectue entre les sites rapprochés du MP7 et ceux rapprochés du MP8-9, ainsi qu’une homogénéisation des espèces entre le nord et le sud de l’Europe. Les sites MP8-9 et ceux proches du MP10 possèdent des faunes de périssodactyles similaires. L’étude phylogénétique indique que les hippomorphes européens sont paraphylétiques, et que les équidés nord-américains s’enracinent dans ce groupe, ainsi que les paléothères européens. Plusieurs évènements de dispersions ont eu lieu très tôt à l’Éocène depuis l’Asie. Deux épisodes de dispersions vers l’Europe ont eu lieu pour les tapiromorphes, un premier (MP7) amenant les isectolophidés qui s’éteindront rapidement en Europe, et un second (MP8-9) apportant des tapiromorphes plus dérivés<br>Perissodactyls (nowadays including horses, rhinos and tapirs) appear at the beginning of the Eocene, and quickly spread into the whole Northern Hemisphere. The center of origin is still debated but the Asian hypothesis is favored, and their phylogenetic affinities are also matter of debate, mostly since the discovery of cambaytheres in India and the genetic affinities with the South American Native Ungulates. This work provides a review of hippomorph perissodactyles of the early Eocene (MP7- MP10) of Europe, and presents a new phylogeny to answer the question of their origin. Most of the material is unpublished and comes from the Paris Basin, as well as Southern France. Twelve hippomorph species, including two new species, and a new species of isectolophid have been identified for the early Eocene of Europe. Faunas close to the MP7 reference-level show differences between Northern and Southern Europe, confirming the hypothesis of a climatic barrier. A turnover of perissodactyls at the generic level takes place between the sites close to MP7 and those close to MP8- 9, and a homogenization of species between Northern and Southern Europe occurs. The sites close to MP8-9 and MP10 have similar perissodactyl faunas. The phylogenetic study indicates that European hippomorphs are paraphyletic, and that North American equids are rooted in this group, as well as European paleotheres. Several dispersal events occurred from Asia very early in the Eocene. Two episodes of dispersions towards Europe took place for the tapiromorphs, a first (MP7) bringing the isectolophids which will go extinct quickly in Europe, and a second one (MP8-9) bringing more derived tapiromorphs
APA, Harvard, Vancouver, ISO, and other styles

Books on the topic "Primitive mammal"

1

R, Lurii͡a A. Ape, primitive man, and child: Essays in the history of behavior. St. Lucie Press, 1998.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Educational, Grolier. World of Animals: Primitive Fish (World of Animals (Danbury, Conn.), V. 31-40.). Grolier, Inc., 2004.

Find full text
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Primitive mammal"

1

Ahnelt, P. K., P. Röhlich, and J. N. Hokoç. "Four cone subtypes in a primitive mammal, the South American opossum - immunocytochemical characterization." In Documenta Ophthalmologica Proceedings Series. Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-011-5408-6_11.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Allin, Edgar F., and James A. Hopson. "Evolution of the Auditory System in Synapsida (“Mammal-Like Reptiles” and Primitive Mammals) as Seen in the Fossil Record." In The Evolutionary Biology of Hearing. Springer New York, 1992. http://dx.doi.org/10.1007/978-1-4612-2784-7_37.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Lewis, Jessica H. "Primitive Australian Mammals." In Comparative Hemostasis in Vertebrates. Springer US, 1996. http://dx.doi.org/10.1007/978-1-4757-9768-8_10.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Jones, Clara B. "Higher “Grades” of Sociality in Class Mammalia: Primitive Eusociality." In SpringerBriefs in Ecology. Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-03931-2_5.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Kemp, T. S. "Evolution of the mammal-like reptiles." In The Origin and Evolution of Mammals. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780198507604.003.0006.

Full text
Abstract:
Mammals, along with the biologically remarkably similar birds, are the vertebrates that are most completely adapted to the physiological rigours of the terrestrial environment. Whilst all the terrestrial dwelling tetrapods can operate in the absence of the buoyancy effect of water, and can use the gaseous oxygen available, mammals have in addition evolved a highly sophisticated ability to regulate precisely the internal temperature and chemical composition of their bodies in the face of the extremes of fluctuating temperature and the dehydrating conditions of dry land. From this perspective, the origin of mammalian biology may be said to have commenced with the emergence of primitive tetrapods onto land around 370 Ma, in the Upper Devonian. Until the 1990s, the only Devonian tetrapod at all well known was Ichthyostega from east Greenland, as described by Jarvik (e.g. Jarvik 1980, 1996). Famous for its combination of primitive fishlike characters such as the lateral line canals, bony rays supporting a tail fin, and remnants of the opercular bones, with fully tetrapod characters such as the loss of the gills and opercular cover, robust ribcage, and of course large feet with digits, Ichthyostega provided more or less all the fossil information there was relating to the transition from a hypothetical rhipidistian fish to a tetrapod. Subsequently, however, an ever-increasing number of other Upper Devonian tetrapods have been described, and the emerging picture of the origin of vertebrate terrestriality has become more complicated and surprising (Ahlberg and Milner 1994; Clack 2002). The earliest forms are Upper Frasnian in age, and include Elginerpeton from the Scottish locality of Scat Craig (Ahlberg 1995, 1998). So far known only from a few bones of the limbs and jaws, Elginerpeton adds little detail to the understanding of the evolution of tetrapods except to demonstrate that the process had commenced at least 10 million years prior to the existence of Ichthyostega. The next oldest tetrapods are Fammenian in age and include Ichthyostega, and a second east Greenland form, Acanthostega, which has been described in great detail (Coates and Clack 1990, 1991; Coates 1996).
APA, Harvard, Vancouver, ISO, and other styles
6

Kemp, T. S. "Evolution of mammalian biology." In The Origin and Evolution of Mammals. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780198507604.003.0007.

Full text
Abstract:
There are large biological differences between the mammals and the primitive living amniotes as represented by turtles, lizards, and crocodiles ● Differentiated dentition with occluding post-canine teeth, and radical reorganisation of jaw musculature to operate them ● Differentiation of vertebral column and limb musculature, and repositioning of limbs to bring feet under the body, increasing agility of locomotion ● Relatively huge brain and highly sensitive sense organs ● Endothermic temperature physiology, with very high metabolic rates, insulation, and high respiratory rates ● Precise osmoregulatory and chemoregulatory abilities using loops of Henle in the kidney and an array of endocrine mechanisms Incomplete as it is, the fossil record of the mammal-like reptiles, or ‘non-mammalian synapsids’ permits the reconstruction of a series of hypothetical intermediate stages that offers considerable insight into how, when, and where this remarkable transition occurred. Deriving these stages starts with a cladogram of the relevant fossils that is then read as an evolutionary tree, with hypothetical ancestors represented by the nodes. The characters that define a node, plus the characters of the previous nodes, constitute the reconstruction. The differences in characters between adjacent nodes represent the evolutionary transitions that by inference occurred, and the whole set of successive nodes generates all that can be inferred about the sequence of acquisition of characters. If a hypothetical ancestral synapsid is placed at the base of the cladogram, and a hypothetical ancestral mammal as the final node, then the set of nodes in between represents everything the fossil record is capable of revealing about the pattern by which mammalian characters evolved: the sequence of their acquisition, the correlations between characters, and possibly the rates of their evolution. Of course, the inferred pattern of evolution of characters is only as reliable as the cladogram which generated it, and that in turn is only as realistic as the model of evolution used in its construction from the character data. And of course, there must have been many intermediate stages in the transition than cannot be reconstructed for want of appropriate fossil representation of those particular grades. Nevertheless, limited as it may be, this is what can be known from the fossil record.
APA, Harvard, Vancouver, ISO, and other styles
7

Kemp, T. S. "Introduction." In The Origin and Evolution of Mammals. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780198507604.003.0004.

Full text
Abstract:
There are about 4,600 species of animals today that are called mammals because, despite an astonishing diversity of form and habitat, they all share a long list of characters not found in any other organisms, such as the presence of mammary glands, the single bone in the lower jaw, and the neocortex of the forebrain. This makes them unambiguously distinct from their closest living relatives, and their unique characters together define a monophyletic taxon, the class Mammalia. Three subgroups are readily distinguished amongst the living mammals. The Monotremata are the egg-laying mammals of Australasia, consisting only of two species of echidna and a single platypus species; for all their primitive reproductive biology, monotremes are fully mammalian in their general structure and biology. The Marsupialia, or Metatheria are the pouched mammals, whose approximately 260 species dominate the mammalian fauna of Australia, and also occur as part of the indigenous fauna of the Americas. By far the largest group of living mammals are the Placentalia, or Eutheria with about 4,350 species divided into usually eighteen recent orders. It is virtually unanimously accepted that the closest living relatives, the sister group, of mammals consists of the reptiles and the birds. The only serious dissent from this view in recent years was that of Gardiner (1982) who advocated that the birds alone and mammals were sister groups, the two constituting a taxon Haemothermia, defined among other characters by the endothermic (‘warm-blooded’) temperature physiology. Gardiner certainly drew attention to some remarkable similarities between birds and mammals, notably the details of the endothermic processes, the enlarged size and surface folding of the cerebellum, and a number of more superficial morphological features. There was also some molecular sequence data supporting the Haemothermia concept, including the beta-globin gene and 18S rRNA. Gardiner’s view briefly became a cause célèbre in part for its sheer heterodoxy, but all concerned have since rejected it on the grounds that a careful, comprehensive analysis of the characters supports the traditional view (Kemp 1988b), particularly if the characters of the relevant fossils are taken into account (Gauthier, Kluge, and Rowe 1988).
APA, Harvard, Vancouver, ISO, and other styles
8

Gheerbrant, Emmanuel. "Primitive Ungulates (“Condylarthra” and Stem Paenungulata)." In Cenozoic Mammals of Africa. University of California Press, 2010. http://dx.doi.org/10.1525/california/9780520257214.003.0028.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Kemp, T. S. "Living and fossil marsupials." In The Origin and Evolution of Mammals. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780198507604.003.0009.

Full text
Abstract:
There are about 265 living species of marsupial mammals, the majority in Australasia, about 60 in South America, and a handful in Central and North America (Macdonald 2001). They are distinguishable from the placental mammals by many characters, but most profoundly by their mode of reproduction. Compared to the placentals, there is only a relatively brief intrauterine period, during which the embryo exchanges nutrients and gases with the mother via a simple, non-invasive yolk sac placenta. There is no development of the complex, highly invasive chorio-allantoic placenta found in the placentals with the partial exception of the bandicoots in which there is a small, short-lived, but true chorio-allantoic placenta. The marsupial neonate is born at a very immature stage, and most of the total maternal provision comes via lactation. In the majority of cases the young are carried in a pouch, although there are exceptions to this. Whether pouched or not, the young attach themselves continuously to the teat for an extended period of time. There has been much discussion about whether the marsupial mode of reproduction is ancestral to that of the placental mammals, or whether it represents an independent, parallel acquisition of viviparity. Lillegraven (1979), Lillegraven et al. (1987), and Szalay (1994), for example, regarded the marsupial mode as primitive and inefficient compared to the placental mode, and that it was failure of the marsupials to evolve a mechanism to prevent immunological rejection of the embryo by the mother that prevented any extension of the gestation period. Placentals, they argued, solved the problem by evolving the trophoblast layer of embryonic cells that performs the function of preventing the maternal antibodies from damaging the embryo. Conversely, several authors such as Parker (1977) have argued that the marsupial mode is an alternative, but equally well-adapted strategy of reproduction to that of placentals. It is one of low investment but low risk, and is therefore suitable for a more unpredictable environment. Tyndale-Biscoe and Renfree (1987) suggested that primitive marsupials and placentals had quite similar reproduction, with relatively immature neonates and a relatively long lactation period. Subsequent specialisation in the two groups went in different directions.
APA, Harvard, Vancouver, ISO, and other styles
10

Coolidge, Frederick L. "The Evolution of Sleep and Dreams." In Evolutionary Neuropsychology. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190940942.003.0009.

Full text
Abstract:
Primitive sleep states developed from earth’s rotational cycle, where activities were constrained by alternating periods of light and dark. Extant reptiles, birds, mammals, and primates exhibit slow-wave sleep (SWS) and rapid eye movement (REM) sleep, which suggests an early evolutionary development dating to at least 300 million years ago or earlier. There may have been no single purpose of sleep, however, multiple reasons for its evolution and different sleep stages have been suggested, including reduced energy demands, facilitation of learning and memory, removal of waste metabolites, priming for subsequently successful waking activities, and aiding creativity. When Homo erectus appeared about 1.9 million years ago, it made a full transition to terrestrial life, including sleeping on the ground instead of in nests in trees. Ground sleep resulted in a single integrated sleep period, which had many positive cognitive repercussions. The design for the Acheulean handaxe, attributed to Homo erectus, may have come to a stone knapper in a dream. Some handaxes, beginning about 500,000 years ago, had aesthetic qualities and may have been used as a means of sexual selection.
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Primitive mammal"

1

Owen, Drew, and Evan Zamir. "The Role of Actomyosin Contractility During Early Avian Gastrulation." In ASME 2010 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/sbc2010-19574.

Full text
Abstract:
Actin-myosin contraction has been shown to play a major role in early morphogenetic movements in Drosophila (fly) and Xenopus (frog) [1,2]. However, the specific role of actomyosin contractility in amniote embryos (reptiles, birds, and mammals) during primitive streak (PS) formation, the “organizing center” for gastrulation (formation of three primary germ layers), is not known. Current theories regarding primitive streak formation in higher order amniotes center around cell-cell intercalation or chemotactic cell movement [3,4]. We hypothesize that contraction via actin-myosin (AM) filaments is conserved from anamniotes and drives formation of the PS and the associated morphogenetic cell movements.
APA, Harvard, Vancouver, ISO, and other styles
2

Henkels, Julia A., and Evan A. Zamir. "A Novel Biomimetic Model for Studying Mechanics of Embryonic Morphogenesis and Differentiation." In ASME 2010 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/sbc2010-19608.

Full text
Abstract:
Before the explosion of genetics research in the last century, embryonic development was largely studied from a mechanical perspective. Paired with genetic advances in understanding developmental signaling pathways and induction mechanisms, an important goal for understanding morphogenesis is to discover how the genome codes for changes in the mechanical movements of the embryonic cells. After formation of the zygote, a phase of rapid mitotic cell division is followed by epithelialization resulting in a cohesive sheet of cells termed the epiblast. During the next major phase of triploblastic development called gastrulation, a group of undifferentiated cells in the epiblast moves collectively to the embryonic midline and eventually gives rise to the three primary germ layers: endoderm, mesoderm, and ectoderm. At the primitive streak—the “organizing center” in amniotes (reptiles, birds, and mammals) which delineates anterior-posterior polarity—prospective endodermal and mesodermal precursors undergo epithelial-to-mesenchymal transition (EMT), internalization, and eventually organogenesis. “It is not birth, marriage, or death, but gastrulation which is truly the most important time in your life” (Lewis Wolpert, 1986).
APA, Harvard, Vancouver, ISO, and other styles
3

Kannan, Nagarajan, Maisam Makarem, Long Nguyen, Jeff Dong, Peter Eirew, and Connie Eaves. "Abstract 2919: Different ROS control mechanisms and mutagenic consequences in primitive subsets of normal human mammary cells." In Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC. American Association for Cancer Research, 2013. http://dx.doi.org/10.1158/1538-7445.am2013-2919.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Dravis, Christopher, and Geoffrey Wahl. "Abstract B64: Sox10 drives tumor progression in breast cancer by reprogramming mammary tumor cells into a state of plasticity resembling primitive neural crest cells." In Abstracts: AACR Special Conference: Advances in Breast Cancer Research; October 7-10, 2017; Hollywood, CA. American Association for Cancer Research, 2018. http://dx.doi.org/10.1158/1557-3125.advbc17-b64.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Primitive mammal"

1

Guerrero Cauqui, Rosario. Tumor neuroectodérmico primitivo endometrial con metástasis bilateral en mama. Siicsalud.com, 2016. http://dx.doi.org/10.21840/siic/153009.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Primitive mammal' for particular source types:
Journal articles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography