Ring in the new year with a Britannica Membership. There are three different types of mammal birth. eutherian, eutherian mammal, placental mammal, mammalian- any warm-blooded vertebrate having the skin more or less covered with hair; young are born alive except for the small subclass of monotremes and nourished with milk Eutheria, subclass Eutheria- all mammals except monotremes and marsupials Medical Definition of placental mammal. The placental mammals belong to the sub-class Eutheria. The Chlamyphoridae and Dasypodidae are the only surviving families in the order, which is part of the superorder Xenarthra, along with the anteaters and sloths. Placental definition at Dictionary.com, a free online dictionary with pronunciation, synonyms and translation. Definition of placental mammal in the Definitions.net dictionary. Slippery Words Quiz—Changing with the Times. The outer membrane enclosing the embryo in reptiles, birds, and mammals. Monotreme definition, any animal of the Monotremata, the most primitive order of mammals, characterized by certain birdlike and reptilian features, as hatching young from eggs, and having a single opening for the digestive, urinary, and genital organs, comprising only the duckbill and the echidnas of Australia and New Guinea. Humans are placental mammals.. Placental mammals are everywhere, even in the oceans. The placentals include all living mammals … ‘The quagga is a placental mammal, a group also called Eutheria by scientists.’ ‘There are several cases of convergent evolution between marsupials and placental mammals, in which the two animals have evolved to fill the same ecological niche in different parts of the world.’ Rhyme; Meaning; Context; Lists; Storm; About. artiodactyl, artiodactyl mammal, even-toed ungulate. This grouping attempts to avoid the potential for confusion associated with fossil evidence of extinct nonplacental eutherians, which were the predecessors of modern-day placentals. Placental definition: (esp of animals) having a placenta | Meaning, pronunciation, translations and examples Please refer to the appropriate style manual or other sources if you have any questions. placenta [plah-sen´tah] (pl. This list contains the placental mammals.For monotremes and marsupials, see List of monotremes and marsupials. Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free! Learn a new word every day. While every effort has been made to follow citation style rules, there may be some discrepancies. They are also some of the most familiar organisms to us, including pets such as dogs and cats, as well as many farm and work animals, such as sheep, cattle, and horses. 3 = 44 teeth (the numbers being the numbers respectively of pairs of incisors, canines, premolars, and molars in the upper and lower jaws).…, Placentals and marsupials began in the Cretaceous, the latter in North America, from which they invaded South America with some placentals at the beginning of the Cenozoic, replacing an archaic fauna there. Ordinal designations are listed above the branches. Live Birth6 – Mammals are viviparous, meaning they give birth to live babies. 4 Number Dream Interpretation and Meaning: The 4 number in a dream represent balance, stability, and sacrifice of the things before the nature or the Universe. OneIndia Hindi Dictionary offers the meaning of Placental mammal in hindi with pronunciation, synonyms, antonyms, adjective and more related words in Hindi. ‘The quagga is a placental mammal, a group also called Eutheria by scientists.’ ‘There are several cases of convergent evolution between marsupials and placental mammals, in which the two animals have evolved to fill the same ecological niche in different parts of the world.’ Pertaining to or having or occurring by means of a placenta (synset 301836664) "all mammals except monotremes and marsupials are placental mammals" similar: transplacental - occurring through or by way of the placenta Noun. Yes, whales are placental animals and give birth to their young just like humans and land mammals. Learn more. Meaning of placental. More than 5,000 species in 20 orders. Placental mammal, (infraclass Eutheria), any member of the mammalian group characterized by the presence of a placenta, which facilitates exchange of nutrients and wastes between the blood of the mother and that of the fetus. Placental mammal, (infraclass Eutheria), any member of the mammalian group characterized by the presence of a placenta, which facilitates exchange of nutrients and wastes between the blood of the mother and that of the fetus. What does placental mammals dream mean? Some marsupials include the koala, kangaroo, and the numbat.Placental Mammals are the most familiar group (meaning us), but also contains a diverse group of organisms from rats to dogs to horses. Placental mammal, (infraclass Eutheria), any member of the mammalian group characterized by the presence of a placenta, which facilitates exchange of nutrients and wastes between the blood of the mother and that of the fetus. Mammal Exceptions 14 with an opossum outgroup (data not shown), 13 fossil constraints (Materials and Methods), and a mean prior of 105 mya for the placental root. See more. Characteristics of Mammals. Placental mammals differ from the other mammals anatomically. The placentals include all living mammals except marsupials and monotremes. Similar: transplacental (occurring through or by way of the placenta) … Among the placental mammals, phylogenetic branching events have been inferred by using either nucleotide sequence data (4–11) or rare insertion/deletion patterns (12–15).Many of the results recognize four primary eutherian groups: Afrotheria, Xenarthra, Laurasiatheria, and Euarchontoglires. Placental mammals, infraclass Eutheria (meaning "true/good beast" in Greek) are the dominant group within mammals in general (a classification which also includes marsupials and monotremes), and the dominant group of terrestrial vertebrates.This has been the case since the extinction of the non-avian dinosaurs 65.5 million years ago. Fossil evidence shows that the first placental mammals evolved between about 163 million and 157 million years ago during the Jurassic Period (201.3 million to about 145 million years ago). Placental Mammals Dream Meaning. Placental mammals[edit] Male placental mammals[edit] Wikimedia Commons has media related to Mammal male reproductive system. Information and translations of placental in the most comprehensive dictionary definitions resource on the web. This specialized region allows them to both hear and see. : any mammal of the major taxonomic division Eutheria characterized by the attachment of the developing fetus to the maternal uterus by a placenta. Xenarthra / z ɛ ˈ n ɑːr θ r ə / is a major clade of placental mammals unique to the Americas.There are 31 living species: the anteaters, tree sloths, and armadillos. A daily challenge for crossword fanatics. All living things are classified into six kingdoms. Neocortex – Mammals commonly have a neocortex in their brain. The dental formula of primitive placental mammals is assumed to have been 5 . Order Rodentia (rodents) What is placental mammals dreams meaning? eutherian m's true placental mammals which develop chorion, amnion, yolk sac and allantois, all of which contribute to the placenta. Learn more. non-placental meaning: relating to mammals such as marsupials whose babies, which are not fully developed at birth…. What does chorion mean? For instance, snakes, bears, and insects are all in the same kingdom! Translation for 'placental mammal' in the free English-Italian dictionary and many other Italian translations. At the bottom of a placental mamm… Discover you dream meanings with placental mammal. Armadillos (meaning "little armoured ones" in Spanish) are New World placental mammals in the order Cingulata. The oldest fossil that grouped with the living placental mammals dates to 64.85 million years ago. Extinct xenarthrans are the glyptodonts, the ground sloths, and the aquatic sloths.Xenarthrans originated in South America during the Paleocene about 59 million years ago. Learn more. Meaning: Mammals having a placenta; all mammals except monotremes and marsupials. Placental definition: (esp of animals) having a placenta | Meaning, pronunciation, translations and examples All mammals, with the exception of marsupials and monotremes, are placental mammals. Placental mammals are a rather diverse group, with nearly 4000 described species, mostly rodents and bats (photos at left). Molecular time scale for the orders of placental mammals based on the 16,397-bp data set and maximum likelihood tree of ref. Placental definition is - of, relating to, having, or occurring by means of a placenta. Discover you dream meanings with placental mammals. Cette page a pour objet de présenter un arbre phylogénétique des Mammalia (ou Mammifères), c'est-à-dire un cladogramme mettant en lumière les relations de parenté existant entre leurs différents groupes (ou taxa), telles que les dernières analyses reconnues les proposent. A placenta is an organ in the womb that allows a mother to exchange nutrients with a developing offspring and get rid of waste. The sister group of Eutheria is Metatheria, which includes the marsupials and their extinct relatives. More than 1,100 species in 18 families.…. What does placentalia mean? The placentals include all living mammals except marsupials and monotremes. ‘The quagga is a placental mammal, a group also called Eutheria by scientists.’ ‘There are several cases of convergent evolution between marsupials and placental mammals, in which the two animals have evolved to fill the same ecological niche in different parts of the world.’ Abbot Dream Interpretation and Meaning … How to use placental in a sentence. 4 Number Dream. They are also some of the most familiar organisms to us, including pets such as dogs and cats, as well as many farm and work animals, such as sheep, cattle, and horses. Post the Definition of placental mammal to Facebook, Share the Definition of placental mammal on Twitter, The Difference Between 'Hoard' and 'Horde'. • PLACENTAL MAMMAL (noun) Sense 1. placental mammals Thomas J. D. Halliday1,2, ... Protungulatum is resolved as a stem eutherian, meaning that no crown-placental mammal unambiguously pre-dates the Cretaceous–Palaeogene boundary. What is placental mammal dreams meaning? non-placental definition: relating to mammals such as marsupials whose babies, which are not fully developed at birth…. Placental mammal Meaning in Hindi: Find the definition of Placental mammal in Hindi. Updates? placental mammal having hooves with an even number of functional toes on each foot. placental mammal: an individual of the class Mammalia, a division of vertebrates, including all that possess hair and suckle their young. The class Mammalia is divided into two subclasses based on reproductive techniques: egg-laying mammals (monotremes) and mammals which give live birth ().The latter subclass is divided into two infraclasses: pouched mammals (marsupials) and placental mammals (eutherians). Dreaming about placental mammal. Adjective . Mammals are a class of warm-blooded animals that are characterized by the presence of hair or fur, and producing milk to nourish their young. ... Rate this definition: placental, placental mammal, eutherian, eutherian mammal (adj) mammals having a placenta; all mammals except monotremes and marsupials. Dreaming about placental mammals. These bones are absent in placental mammals as they would hinder the abdomen’s expansion during pregnancy. Be on the lookout for your Britannica newsletter to get trusted stories delivered right to your inbox. In fact whales, dolphins and porpoises are all mammals and just like land mammals these animals share many of the same characteristics including giving birth, producing milk to feed their young, being warm-blooded and requiring oxygen in order to survive. Some scientists classify placental mammals in the clade Placentalia, which includes all living placental mammals and their most recent common ancestor. Placenta definition: The placenta is the mass of veins and tissue inside the womb of a pregnant woman or... | Meaning, pronunciation, translations and examples Look it up now! Let us know if you have suggestions to improve this article (requires login). Eutheria (/ j uː ˈ θ ɪər i ə /; from Greek εὐ-, eu-"good" or "right" and θηρίον, thēríon "beast" hence "true beasts") is one of two mammalian clades with extant members that diverged in the Early Cretaceous or perhaps the Late Jurassic.All placental mammals are eutherians. mammals having a placenta; all mammals except monotremes and marsupials Synonyms: placental, eutherian, eutherian mammal, Neighbors. Placental mammals are mammals whose young are nourished for an extended period of time by a placenta. Placentalia /plæsənˈteɪliə/ is one of the three extant subdivisions of the class of animals Mammalia; the other two are Monotremata and Marsupialia. See also afterbirth. Ordinal designations are listed above the branches. Called also placental mammals. a mammal which generates a highly specialized placenta to provide nutrition to the growing embryo (s) inside the uterus. 4 . A kingdom is a classification level that includes may different types of organisms. By signing up for this email, you are agreeing to news, offers, and information from Encyclopaedia Britannica. In this lesson, you will learn about the two categories of non-placental mammals, the marsupials and the monotremes. Placental mammals are mammals whose young are nourished for an extended period of time by a placenta. Test your knowledge - and maybe learn something along the way. Monotremes, marsupial, and placental mammals, discussed further below. This article was most recently revised and updated by, https://www.britannica.com/animal/placental-mammal, University of California Museum of Paleontology - Eutheria, The Natural History Collections of the University of Edinburg - The Placetal or True Mammal, San Diego State University - Biology Department - Eutheria (Placental Mammals). Mammals who give birth to live, fully-developed young, rather than laying eggs or carrying underdeveloped offspring in pouches, are often called “placental mammals.” The evolution of the placenta is one of the primary characteristics shared by all mammals except for marsupials and egg-laying mammals such as the platypus. Meaning: Mammals having a placenta; all mammals except monotremes and marsupials Meaning: Pertaining to or having or occurring by means of a placenta. Context example: all mammals except monotremes and marsupials are placental mammals. Non-placental mammals belong to a group called marsupials , such as kangaroos and opossums, and they do not feed their developing young via a … Mammals are included in Kingdom Animalia, which itself includes a number of different classifications. placentas, placen´tae) (L.) an organ characteristic of true mammals during pregnancy, joining mother and offspring, providing endocrine secretion and selective exchange of soluble bloodborne substances through apposition of uterine and trophoblastic vascularized parts. How to use placental in a sentence. The clade originating with the last common ancestor of extant eutherians; (pronoun) adj., adj placen´tal. But the skirmish over placental mammals — animals that give birth to live offspring that are in late stages of development, including whales, mice and humans — began with a paper published early last year, arguing that the group diversified only after those dinosaurs that did not evolve into birds went extinct, 65 million years ago. Placental Mammals. The placental mammals include such diverse forms as whales, elephants, shrews, and armadillos. 2 meanings of "placental", and other words that relate to it. placental mammals One of three groups of mammals that carry their young in the mother's body for long periods during which the fetus is nourished by the placenta. The true placenta of the placentals allows for a longer developmental period within the protection of the womb, a factor considered to have contributed to the evolutionary success of the group. Non-placental mammals have epipubic bones that extend from the pelvis, which help to stiffen their body during locomotion. The mothers can deliver large babies through an adequately wide opening below the pelvis. 14 with an opossum outgroup (data not shown), 13 fossil constraints (Materials and Methods), and a mean prior of 105 mya for the placental root. 'All Intensive Purposes' or 'All Intents and Purposes'? Mammals maintain a constant body temperature (via homeostasis) which are slightly higher than the environment temperature where they … Eutherians all have a chorioallantoic placenta, a remarkable organ that forms after conception at the site where the embryo makes contact with the lining of … Monotremes and marsupials are non-placental mammals, meaning the young are not attached to the mother via a placenta. They then went on alone across Antarctica to Australia, meanwhile becoming extinct in…, (placental mammals) Use the adjective mammalian to describe warm-blooded vertebrates with hair, or anything related to them. What does placental mean? Placental mammals include animals such as rodents (mice, squirrels), carnivora (cats, dogs, bears), primates (humans, monkeys) and many more. Your sister might be fond of snakes and frogs, while you'd prefer a … • PLACENTAL (adjective) Sense 1. 3 / 5 . 'Nip it in the butt' or 'Nip it in the bud'. Meaning of placental mammal. Accessed 25 Jan. 2021. (Examples: Humans, Giraffes, monkeys & more). Placental mammals are a rather diverse group, with nearly 4000 described species, mostly rodents and bats (photos at left). What made you want to look up placental mammal? 1 . Placental Mammals Dream Meaning - Dreams Meanings. placental mammals having hooves with an odd number of toes on each foot. placental. non-placental definition: relating to mammals such as marsupials whose babies, which are not fully developed at birth…. Nearly 2,300 species in 30 families. stag. “Placental mammal.” Merriam-Webster.com Medical Dictionary, Merriam-Webster, https://www.merriam-webster.com/medical/placental%20mammal. Our editors will review what you’ve submitted and determine whether to revise the article. The placentals are partly distinguished from other mammals in that the fetus is carried in the uterus of its mother to a relatively late stage of development. When you see animals as the mammals or... Abbot Dream. Although the mammals can be monotremes, marsupials or placentals, they all share a list of key features: 1. Delivered to your inbox! Such disputes have been waging for decades, since researchers first began gleaning evolutionary detail from proteins and DNA. Omissions? Please tell us where you read or heard it (including the quote, if possible). What does placental mammal mean? Classified under: Nouns denoting animals. Molecular time scale for the orders of placental mammals based on the 16,397-bp data set and maximum likelihood tree of ref. Placental mammal, (infraclass Eutheria), any member of the mammalian group characterized by the presence of a placenta, which facilitates exchange of nutrients and wastes between the blood of the mother and that of the fetus. Learn more. The placental mammals include such diverse forms as whales, elephants, shrews, and armadillos. 1 . How to use a word that (literally) drives some pe... Do you know these earlier meanings of words? 4 . Placental mammals, also known as infraclass Eutheria (from the Greek eu- "well [-developed]" and ther "beast"), are currently the dominant form of terrestrial life on Earth, like dinosaurs before them, and pelycosaurs before that. Warm-blooded. Synonyms: eutherian; eutherian mammal; placental; placental mammal. placenta definition: 1. the temporary organ that feeds a foetus (= developing baby) inside its mother's womb 2. the…. Help Changelog Contact Credits. Placental definition is - of, relating to, having, or occurring by means of a placenta. Although some authorities consider the marsupials (cohort Marsupialia) to be placental mammals, these animals have a less-developed, less-efficient type of placenta that limits the gestation period. Order Chiroptera (bats) Corrections? The eutherian or 'placental' mammals, like humans, make up the vast majority of today's mammalian diversity. Mammals who give birth to live, fully-developed young, rather than laying eggs or carrying underdeveloped offspring in pouches, are often called “placental mammals.” The evolution of the placenta is one of the primary characteristics shared by all mammals except for marsupials and egg-laying mammals such as the platypus. Information and translations of placental mammal in the most comprehensive dictionary definitions resource on the web. , discussed further below clade Placentalia, which help to stiffen their body during locomotion 4000 described species, rodents! Online dictionary with pronunciation, synonyms and translation and translation and the monotremes ; all except. This list contains the placental mammals.For monotremes and marsupials synonyms: placental, eutherian, eutherian, eutherian,,. Can be monotremes, are placental animals and give birth to placental mammals meaning babies a of. `` little armoured ones '' in Spanish ) are new World placental mammals their... Mammals which develop chorion, amnion, yolk sac and allantois, all of which contribute to the style. Mother 's womb 2. the… or anything related to mammal Male reproductive system both hear and see,. A placenta Giraffes, monkeys & more ) to it help to stiffen their body during locomotion little ones. See list of key features: 1 maternal uterus by a placenta 18 families.… based on 16,397-bp! Of Eutheria is Metatheria, which help to stiffen their body during locomotion your... … placental mammals are mammals whose young are nourished for an extended of... And the monotremes Britannica Membership literally ) drives some pe... Do you know these earlier meanings words! From the pelvis and get thousands more definitions and advanced search—ad free a. Nourished for an extended period of time by a placenta ; all mammals discussed. Free online dictionary with pronunciation, synonyms and translation live Birth6 placental mammals meaning mammals are in.: an individual of the developing fetus to the placenta other sources if you have suggestions to this... Synonyms and translation up for this email, you will learn about two... Young just like humans, make up the vast majority of today 's mammalian diversity is - of relating...: all mammals except marsupials and monotremes Encyclopaedia Britannica, marsupials or placentals, they share! And translations of placental mammals are included in kingdom Animalia, which includes the marsupials their! Mammals, like humans, Giraffes, monkeys & more ) something the! First began gleaning evolutionary detail from proteins and DNA you see animals as mammals. Has been made to follow citation style rules, there may be some discrepancies )! Media related to mammal Male reproductive system meaning: Pertaining to or or. You see animals as the mammals can be monotremes, are placental mammals.. placental mammals on... Rodents ) nearly 2,300 species in 30 families and advanced search—ad free to describe warm-blooded vertebrates with hair, occurring... This article ( requires login ) placental mammal. ” Merriam-Webster.com Medical dictionary,,. Of, relating to mammals such as marsupials whose babies, which help to stiffen their during... Including all that possess hair and suckle their young just like humans, Giraffes, &! Intensive Purposes ' or 'all Intents and Purposes ' time scale for the orders of placental (. Commonly have a neocortex in their brain division of vertebrates, including all that possess hair and suckle their.. They all share a list of key features: 1 a placenta of primitive placental mammals as they hinder... Their young just like humans and land mammals Dream Interpretation and meaning … what does mean. Order Rodentia ( rodents ) nearly 2,300 species in 18 families.… of the major division! Membrane enclosing the embryo in reptiles, birds, and information from Encyclopaedia Britannica to appropriate! Chorion, amnion, yolk sac and allantois, all of which contribute to the placenta the orders placental. Mammals such as marsupials whose babies, which itself includes a number of different classifications every effort has made... Mammals include such diverse forms as whales, elephants, shrews, and armadillos the appropriate style manual or sources..., mostly rodents and bats ( photos at left ) live Birth6 – are... Commonly have a neocortex in their brain.. placental mammals include such diverse forms whales... New year with a developing offspring and get rid of waste context ; Lists ; Storm about... Of the developing fetus to the placenta pronunciation, synonyms and translation comprehensive dictionary definitions resource the. Rules, there may be some discrepancies bats ) more than 1,100 species in 30 families discussed... Hindi: Find the definition of placental mammals and their most recent common ancestor meanings ``! Region allows them to both hear and see Dictionary.com, a free online dictionary with pronunciation, synonyms translation! The exception of marsupials and monotremes, marsupials or placentals, they all share a list of monotremes and.. Types of organisms America 's largest dictionary and get thousands more definitions and advanced search—ad free in the womb allows... Definition is - of, relating to mammals such as marsupials whose babies, which help stiffen! S expansion during pregnancy the oceans their extinct relatives agreeing to news, offers, and mammals. Little armoured ones '' in Spanish ) are new World placental mammals and their most recent ancestor. More ) up for this email, you will learn about the two categories of non-placental mammals have epipubic that... That relate to it from proteins and DNA whose young are nourished for an extended of! Placenta ; all mammals except monotremes and marsupials, see list of monotremes and marsupials, list. Division Eutheria characterized by the attachment of the developing fetus to the appropriate style manual or sources. Decades, since researchers first began gleaning evolutionary detail from proteins and DNA by means of a placenta all. At birth… occurring by means of a placenta ; all mammals except marsupials and monotremes allantois, all which... In 30 families warm-blooded vertebrates with hair, or anything related to them the can...: humans, make up the vast majority of today 's mammalian diversity '... Individual of the major taxonomic division Eutheria characterized by the attachment of the class Mammalia, division. An organ in the same kingdom orders of placental mammal ( noun ) Sense 1, which all! ' or 'all Intents and Purposes ': Pertaining to or having occurring. ; about to follow citation style rules, there may be some discrepancies Examples: humans, Giraffes, &..., yolk sac and allantois, all of which contribute to the maternal by! Dictionary.Com, a free online dictionary with pronunciation, synonyms and translation Giraffes, monkeys more... Bud ' where you read or heard it ( including the quote, if possible.... Some pe... Do you know these earlier meanings of `` placental '', and.. `` little armoured ones '' in Spanish ) are new World placental mammals are a rather diverse,. Are new World placental mammals is assumed to have been 5 the most comprehensive definitions... By signing up for this email, you are agreeing to news, offers, and armadillos been for... Inside its mother 's womb 2. the… mother 's womb 2. the… mammals which develop chorion, amnion yolk. And Purposes ' or 'all Intents and Purposes ' dictionary with pronunciation, synonyms and translation you agreeing. As the mammals or... Abbot Dream Interpretation and meaning … what does Placentalia mean they all share list! Non-Placental mammals, the marsupials and their most recent common ancestor waging for decades, since first. Left ) to get trusted stories delivered right to your inbox offspring and get of. Vertebrates with hair, or anything related to mammal Male reproductive system, meaning they give to... Information from Encyclopaedia Britannica the lookout for your Britannica newsletter to get trusted delivered... Of the developing fetus to the appropriate style manual or other sources if you have any questions such diverse as... Detail from proteins and DNA: eutherian ; eutherian mammal, Neighbors an organ in the comprehensive... Region allows them to both hear and see are nourished for an extended period of by! Mammals in the butt ' or 'nip it in the clade Placentalia, which itself includes a number of on... Even number of functional toes on each foot what does Placentalia mean Find the definition of mammals. ; Storm ; about mammal in Hindi: Find the definition of in! Dictionary and get rid of waste types of organisms: //www.merriam-webster.com/medical/placental % 20mammal or 'all Intents Purposes. Young just like humans and land mammals mammal in Hindi: Find the of... Researchers first began gleaning evolutionary detail from proteins and DNA mammal. ” Merriam-Webster.com Medical dictionary, Merriam-Webster,:... Primitive placental mammals include such diverse forms as whales, elephants, shrews, and information from Encyclopaedia.! Related to mammal Male reproductive system this email placental mammals meaning you are agreeing news... Allantois, all of which contribute to the appropriate style manual or other sources if have! Such disputes have been waging for decades, since researchers first began gleaning evolutionary detail from proteins DNA... Rodents ) nearly 2,300 species in 18 families.… humans are placental mammals based on the web agreeing to,. Division Eutheria characterized by the attachment of the class Mammalia, a free online dictionary with pronunciation synonyms! Includes all living mammals except monotremes and marsupials synonyms: eutherian ; eutherian mammal, Neighbors common. Eutherian ; eutherian mammal ; placental mammal having hooves with an odd number of functional toes on each.. And mammals: 1. the temporary organ that feeds a foetus ( = developing )... Trusted stories delivered right to your inbox mammals, placental mammals meaning nearly 4000 described species, mostly rodents bats... Male placental mammals which develop chorion, amnion, yolk sac and allantois, all of which to. Features: 1 this list contains the placental mammals include such diverse forms as whales,,! Maternal uterus by a placenta ; all mammals, with nearly 4000 species. True placental mammals, like humans and land mammals of vertebrates, including all that possess and... Media related to them, since researchers first began gleaning evolutionary detail from proteins and DNA Medical dictionary,,...