Терапсида
| Терапсида Временный диапазон:
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| Сверху вниз и слева направо, несколько примеров не млекопитающих терапсидов: биармосухус ( биармосухия ), мосшопы ( диноцефалия ), листрозавр ( аномодонтия ), inostrancevia (горгонопсия ), ) и Чиникодон ( Гланосухух ( Тероцефалия Cynodontia ), Glanosuchus ( Тероцефалия ) и Chiniquodon ( Cynodontia ), Glanosuchus (Thropephalia ) и Chint | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Synapsida |
| Clade: | Sphenacodontia |
| Clade: | Pantherapsida |
| Clade: | Sphenacodontoidea |
| Clade: | Therapsida Broom, 1905[1] |
| Clades | |
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Терапсида [ А ] это клада, включающая основную группу эупеликозавровских синапсидов , которая включает в себя млекопитающих , их предков и близких родственников. Многие из черт, сегодня считавшихся уникальными для млекопитающих, имели свое происхождение в ранних терапидах, включая конечности, которые были более ориентированы под телом, что привело к более «стоящей» четвероночной осанке, в отличие от более низкой обширной осанки многих рептилий и амфибий .
Терапсиды развивались из более ранних синапсидов, обычно называемых « пеликозаврами », особенно в сфенакодонтии , более 279,5 миллионов лет назад. Они заменили пеликозавров как доминирующих крупных земельных животных в гуадалупии до раннего триаса. После того, как пермс -триассическая вымирание терапиды снизились в относительной важности для быстро диверсифицирующих архозаврианских сауропсидов ( псевдосухийцы , динозавры и птерозавры и т. Д.) Во время среднего триаса.
Therapsids включают в себя Cynodonts , группу, которая породила млекопитающих ( млекопитающие ) в позднем триасе около 225 миллионов лет назад, единственную терапистскую кладу, которая выжила до конца триаса . Единственная другая группа терапидов, которая выжила в позднем триасе , дицинодонтах , вымерших к концу периода. Последней сохранившейся группой не намычных цинодонтов была TrityLodontidae , которая вымерла во время раннего мелового .
Characteristics
[edit]
Jaw and teeth
[edit]Therapsids' temporal fenestrae were larger than those of the pelycosaurs. The jaws of some therapsids were more complex and powerful, and the teeth were differentiated into frontal incisors for nipping, great lateral canines for puncturing and tearing, and molars for shearing and chopping food.
Posture
[edit]Therapsid legs were positioned more vertically beneath their bodies than were the sprawling legs of reptiles and pelycosaurs. Also compared to these groups, the feet were more symmetrical, with the first and last toes short and the middle toes long, an indication that the foot's axis was placed parallel to that of the animal, not sprawling out sideways. This orientation would have given a more mammal-like gait than the lizard-like gait of the pelycosaurs.[2]
Physiology
[edit]The physiology of therapsids is poorly understood. Most Permian therapsids had a pineal foramen, indicating that they had a parietal eye like many modern reptiles and amphibians. The parietal eye serves an important role in thermoregulation and the circadian rhythm of ectotherms, but is absent in modern mammals, which are endothermic.[3] Near the end of the Permian, dicynodonts, therocephalians and cynodonts show parallel trends towards loss of the pineal foramen, and the foramen is completely absent in probainognathian cynodonts. Evidence from oxygen isotopes, which are correlated with body temperature, suggests that most Permian therapsids were ectotherms and that endothermy evolved convergently in dicynodonts and cynodonts near the end of the Permian.[4] In contrast, evidence from histology suggests that endothermy is shared across Therapsida,[5] whereas estimates of blood flow rate and lifespan in the mammaliaform Morganucodon suggest that even early mammaliaforms had reptile-like metabolic rates.[6] Evidence for respiratory turbinates, which have been hypothesized to be indicative of endothermy, was reported in the therocephalian Glanosuchus, but subsequent study showed that the apparent attachment sites for turbinates may simply be the result of distortion of the skull.[7]
Integument
[edit]The evolution of integument in therapsids is poorly known, and there are few fossils that provide direct evidence for the presence or absence of fur. The most basal synapsids with unambiguous direct evidence of fur are docodonts, which are mammaliaforms very closely related to crown-group mammals. Two "mummified" juvenile specimens of the dicynodont Lystrosaurus murrayi preserve skin impressions; the skin is hairless, leathery, and dimpled, somewhat comparable to elephant skin.[8][9] Fossilized facial skin from the dinocephalian Estemmenosuchus has been described as showing that the skin was glandular and lacked both scales and hair.[10]
Coprolites containing what appear to be hairs have been found from the Late Permian.[11][12] Though the source of these hairs is not known with certainty, they may suggest that hair was present in at least some Permian therapsids.
The closure of the pineal foramen in probainognathian cynodonts may indicate a mutation in the regulatory gene Msx2, which is involved in both the closure of the skull roof and the maintenance of hair follicles in mice.[13] This suggests that hair may have first evolved in probainognathians, though it does not entirely rule out an earlier origin of fur.[13]
Whiskers probably evolved in probainognathian cynodonts.[13][14] Some studies had inferred an earlier origin for whiskers based on the presence of foramina on the snout of therocephalians and early cynodonts, but the arrangement of foramina in these taxa actually closely resembles lizards,[15] which would make the presence of mammal-like whiskers unlikely.[14]
Evolutionary history
[edit]
Therapsids evolved from a group of pelycosaurs called sphenacodonts.[17][18] Therapsids became the dominant land animals in the Middle Permian, displacing the pelycosaurs. Therapsida consists of four major clades: the dinocephalians, the herbivorous anomodonts, the carnivorous biarmosuchians, and the mostly carnivorous theriodonts. After a brief burst of evolutionary diversity, the dinocephalians died out in the later Middle Permian (Guadalupian) but the anomodont dicynodonts as well as the theriodont gorgonopsians and therocephalians flourished, being joined at the very end of the Permian by the first of the cynodonts.
Like all land animals, the therapsids were seriously affected by the Permian–Triassic extinction event, with the very successful gorgonopsians and the biarmosuchians dying out altogether and the remaining groups—dicynodonts, therocephalians and cynodonts—reduced to a handful of species each by the earliest Triassic. Surviving dicynodonts were represented by two families of disaster taxa (Lystrosauridae and Myosauridae), the scarcely known Kombuisia, and a single group of large stocky herbivores, the Kannemeyeriiformes, which were the only dicynodont lineage to thrive during the Triassic.[20] They and the medium-sized cynodonts (including both carnivorous and herbivorous forms) flourished worldwide throughout the Early and Middle Triassic. They disappear from the fossil record across much of Pangea at the end of the Carnian (Late Triassic), although they continued for some time longer in the wet equatorial band and the south.[citation needed]
Some exceptions were the still further derived eucynodonts.[21] At least three groups of them survived. They all appeared in the Late Triassic period. The extremely mammal-like family, Tritylodontidae, survived into the Early Cretaceous. Another extremely mammal-like family, Tritheledontidae, are unknown later than the Early Jurassic. Mammaliaformes was the third group, including Morganucodon and similar animals. Some taxonomists refer to these animals as "mammals", though most limit the term to the mammalian crown group.
The non-eucynodont cynodonts survived the Permian–Triassic extinction; Thrinaxodon, Galesaurus and Platycraniellus are known from the Early Triassic. By the Middle Triassic, however, only the eucynodonts remained.
The therocephalians, relatives of the cynodonts, managed to survive the Permian–Triassic extinction and continued to diversify through the Early Triassic period. Approaching the end of the period, however, the therocephalians were in decline to eventual extinction, likely outcompeted by the rapidly diversifying Saurian lineage of diapsids, equipped with sophisticated respiratory systems better suited to the very hot, dry and oxygen-poor world of the End-Triassic.
Dicynodonts were among the most successful groups of therapsids during the Late Permian, and survived through to near the end of the Triassic.
Mammals are the only living therapsids. The mammalian crown group, which evolved in the Early Jurassic period, radiated from a group of mammaliaforms that included the docodonts. The mammaliaforms themselves evolved from probainognathians, a lineage of the eucynodont suborder.
Classification
[edit]| The Hopson and Barghausen paradigm for therapsid relationships |
Six major groups of therapsids are generally recognized: Biarmosuchia, Dinocephalia, Anomodontia, Gorgonopsia, Therocephalia and Cynodontia. A clade uniting therocephalians and cynodonts, called Eutheriodontia, is well supported, but relationships among the other four clades are controversial.[23] The most widely accepted hypothesis of therapsid relationships, the Hopson and Barghausen paradigm, was first proposed in 1986. Under this hypothesis, biarmosuchians are the earliest-diverging major therapsid group, with the other five groups forming the Eutherapsida, and within Eutherapsida, gorgonopsians are the sister taxon of eutheriodonts, together forming the Theriodontia. Hopson and Barghausen did not initially come to a conclusion about how dinocephalians, anomodonts and theriodonts were related to each other, but subsequent studies suggested that anomodonts and theriodonts should be classified together as the Neotherapsida. However, there remains debate over these relationships; in particular, some studies have suggested that anomodonts, not gorgonopsians, are the sister taxon of Eutheriodontia, other studies have found dinocephalians and anomodonts to form a clade, and both the phylogenetic position and monophyly of Biarmosuchia remain controversial.
In addition to the six major groups, there are several other lineages and species of uncertain classification. Raranimus from the early Middle Permian of China is likely to be the earliest-diverging known therapsid.[24] Tetraceratops from the Early Permian of the United States has been hypothesized to be an even earlier-diverging therapsid,[25][26] but more recent study has suggested it is more likely to be a non-therapsid sphenacodontian.[27]
Biarmosuchia
[edit]
Biarmosuchia is the most recently recognized therapsid clade, first recognized as a distinct lineage by Hopson and Barghausen in 1986 and formally named by Sigogneau-Russell in 1989. Most biarmosuchians were previously classified as gorgonopsians. Biarmosuchia includes the distinctive Burnetiamorpha, but support for the monophyly of Biarmosuchia is relatively low. Many biarmosuchians are known for extensive cranial ornamentation.
Dinocephalia
[edit]
Dinocephalia comprises two distinctive groups, the Anteosauria and Tapinocephalia.
Historically, carnivorous dinocephalians, including both anteosaurs and titanosuchids, were called titanosuchians and classified as members of Theriodontia, while the herbivorous Tapinocephalidae were classified as members of Anomodontia.
Anomodontia
[edit]
Anomodontia includes the dicynodonts, a clade of tusked, beaked herbivores, and the most diverse and long-lived clade of non-cynodont therapsids. Other members of Anomodontia include Suminia, which is thought to have been a climbing form.
Gorgonopsia
[edit]
Gorgonopsia is an abundant but morphologically homogeneous group of saber-toothed predators.
Therocephalia
[edit]
It has been suggested that Therocephalia might not be monophyletic, with some species more closely related to cynodonts than others.[28] However, most studies regard Therocephalia as monophyletic.
Cynodontia
[edit]
Cynodonts are the most diverse and longest-lived of the therapsid groups, as Cynodontia includes mammals. Cynodonts are the only major therapsid clade to lack a Middle Permian fossil record, with the earliest-known cynodont being Charassognathus from the Wuchiapingian age of the Late Permian. Non-mammalian cynodonts include both carnivorous and herbivorous forms.
See also
[edit]Notes
[edit]References
[edit]- ^ Broom, R. (1905). "On the use of the term Anomodontia". Records of the Albany Museum. 1 (4): 266–269.
- ^ Carroll, R. L. (1988). Vertebrate Paleontology and Evolution. New York: W. H. Freeman and Company. pp. 698. ISBN 978-0-7167-1822-2.
- ^ Benoit, Julien; Abdala, Fernando; Manger, Paul; Rubidge, Bruce (2016). "The sixth sense in mammalians forerunners: variability of the parietal foramen and the evolution of the pineal eye in South African Permo-Triassic eutheriodont therapsids". Acta Palaeontologica Polonica. doi:10.4202/app.00219.2015. ISSN 0567-7920. S2CID 59143925.
- ^ Rey, Kévin; Amiot, Romain; Fourel, François; Abdala, Fernando; Fluteau, Frédéric; Jalil, Nour-Eddine; Liu, Jun; Rubidge, Bruce S; Smith, Roger MH; Steyer, J Sébastien; Viglietti, Pia A; Wang, Xu; Lécuyer, Christophe (18 July 2017). "Oxygen isotopes suggest elevated thermometabolism within multiple Permo-Triassic therapsid clades". eLife. 6: –28589. doi:10.7554/eLife.28589. ISSN 2050-084X. PMC 5515572. PMID 28716184.
- ^ Faure-Brac, Mathieu G.; Cubo, Jorge (2 March 2020). "Were the synapsids primitively endotherms? A palaeohistological approach using phylogenetic eigenvector maps". Philosophical Transactions of the Royal Society B: Biological Sciences. 375 (1793): 20190138. doi:10.1098/rstb.2019.0138. ISSN 1471-2970. PMC 7017441. PMID 31928185.
- ^ Newham, Elis; Gill, Pamela G.; Brewer, Philippa; Benton, Michael J.; Fernandez, Vincent; Gostling, Neil J.; Haberthür, David; Jernvall, Jukka; Kankaanpää, Tuomas; Kallonen, Aki; Navarro, Charles; Pacureanu, Alexandra; Richards, Kelly; Brown, Kate Robson; Schneider, Philipp; Suhonen, Heikki; Tafforeau, Paul; Williams, Katherine A.; Zeller-Plumhoff, Berit; Corfe, Ian J. (2020). "Reptile-like physiology in Early Jurassic stem-mammals". Nature Communications. 11 (1): 5121. Bibcode:2020NatCo..11.5121N. doi:10.1038/s41467-020-18898-4. ISSN 2041-1723. PMC 7550344. PMID 33046697.
- ^ Hopson, James A. (18 October 2012). "The Role of Foraging Mode in the Origin of Therapsids: Implications for the Origin of Mammalian Endothermy". Fieldiana Life and Earth Sciences. 5: 126–148. doi:10.3158/2158-5520-5.1.126. ISSN 2158-5520. S2CID 84471370.
- ^ Smith, Roger M.H.; Botha, Jennifer; Viglietti, Pia A. (15 October 2022). "Taphonomy of drought afflicted tetrapods in the Early Triassic Karoo Basin, South Africa". Palaeogeography, Palaeoclimatology, Palaeoecology. 604: 111207. Bibcode:2022PPP...60411207S. doi:10.1016/j.palaeo.2022.111207.
- ^ Timmons, Jeanne (20 September 2022). "These Fossil Mummies Reveal a Brutal World Long Before T. Rex Lived". Gizmodo. Retrieved 25 July 2024.
- ^ Chudinov, P. K. (1968). "Structure of the integuments of theromorphs". Doklady Akad. Nauk SSSR. 179: 226–229.
- ^ Smith, Roger M.H.; Botha-Brink, Jennifer (2011). "Morphology and composition of bone-bearing coprolites from the Late Permian Beaufort Group, Karoo Basin, South Africa". Palaeogeography, Palaeoclimatology, Palaeoecology. 312 (1–2): 40–53. Bibcode:2011PPP...312...40S. doi:10.1016/j.palaeo.2011.09.006. ISSN 0031-0182.
- ^ Bajdek, Piotr; Qvarnström, Martin; Owocki, Krzysztof; Sulej, Tomasz; Sennikov, Andrey G.; Golubev, Valeriy K.; Niedźwiedzki., Grzegorz (2016). "Microbiota and food residues including possible evidence of pre-mammalian hair in Upper Permian coprolites from Russia". Lethaia. 49 (4): 455–477. Bibcode:2016Letha..49..455B. doi:10.1111/let.12156.
- ^ Jump up to: a b c Benoit, J.; Manger, P. R.; Rubidge, B. S. (9 May 2016). "Palaeoneurological clues to the evolution of defining mammalian soft tissue traits". Scientific Reports. 6 (1): 25604. Bibcode:2016NatSR...625604B. doi:10.1038/srep25604. ISSN 2045-2322. PMC 4860582. PMID 27157809.
- ^ Jump up to: a b Benoit, Julien; Ruf, Irina; Miyamae, Juri A.; Fernandez, Vincent; Rodrigues, Pablo Gusmão; Rubidge, Bruce S. (2020). "The Evolution of the Maxillary Canal in Probainognathia (Cynodontia, Synapsida): Reassessment of the Homology of the Infraorbital Foramen in Mammalian Ancestors". Journal of Mammalian Evolution. 27 (3): 329–348. doi:10.1007/s10914-019-09467-8. ISSN 1573-7055. S2CID 156055693.
- ^ Estes, Richard (1961). "Cranial anatomy of the cynodont reptile Thrinaxodon liorhinus". Bulletin of the Museum of Comparative Zoology. 125: 165–180.
- ^ Liu, Jun; Rubidge, Bruce; and Li, Jinling (2009). "New basal synapsid supports Laurasian origin for therapsids" (PDF). Acta Palaeontologica Polonica. 54 (3): 393–400. doi:10.4202/app.2008.0071. Retrieved 25 September 2009.
- ^ Synapsid Classification & Apomorphies
- ^ Huttenlocker, Adam K. and Rega, Elizabeth (2012). "Chapter 4. The Paleobiology and Bone Microstructure of Pelycosauriangrade Synapsids". In Chinsamy-Turan, Anusuya (ed.). Forerunners of Mammals: Radiation, Histology, Biology. Indiana University Press. pp. 90–119. ISBN 978-0253005335.
- ^ Benoit, Julien; Norton, Luke A.; Manger, Paul R.; and Rubidge, Bruce S. (2017). Claessens, Leon (ed.). "Reappraisal of the envenoming capacity of Euchambersia mirabilis (Therapsida, Therocephalia) using μCT-scanning techniques". PLOS ONE. 12 (2): e0172047. Bibcode:2017PLoSO..1272047B. doi:10.1371/journal.pone.0172047. PMC 5302418. PMID 28187210.
- ^ Kammerer, Christian F.; Fröbisch, Jörg; Angielczyk, Kenneth D. (31 May 2013). Farke, Andrew A. (ed.). "On the Validity and Phylogenetic Position of Eubrachiosaurus browni, a Kannemeyeriiform Dicynodont (Anomodontia) from Triassic North America". PLOS ONE. 8 (5): e64203. Bibcode:2013PLoSO...864203K. doi:10.1371/journal.pone.0064203. ISSN 1932-6203. PMC 3669350. PMID 23741307.
- ^ Padian, Kevin (4 September 2013). "A Review of "Forerunners of Mammals: Radiation, Histology, Biology"". Journal of Vertebrate Paleontology. 33 (5): 1250–1251. Bibcode:2013JVPal..33.1250P. doi:10.1080/02724634.2013.763814. ISSN 0272-4634.
- ^ Geggel, L. (2016). "Meet the Ancient Reptile that Gave Rise to Mammals". Scientific American.
- ^ Angielczyk, Kenneth D.; Kammerer, Christian F. (22 October 2018). "Non-Mammalian synapsids: the deep roots of the mammalian family tree". In Zachos, Frank; Asher, Robert (eds.). Mammalian Evolution, Diversity and Systematics. De Gruyter. pp. 117–198. doi:10.1515/9783110341553-005. ISBN 978-3-11-034155-3. S2CID 92370138.
- ^ Duhamel, A.; Бенуа, Дж.; Рубидж, BS & Liu, J. (август 2021 г.). «Повторная оценка самого старого TherapsId Raranimus подтверждает его статус базального члена клады и заполняет разрыв Олсона» . Наука природы . 108 (4): 26. Bibcode : 2021scina.108 ... 26d . doi : 10.1007/s00114-021-01736-y . ISSN 0028-1042 . PMID 34115204 . S2CID 235403632 .
- ^ Лаурин, М.; Reisz, RR (1996). «Остеология и отношения тетрацератопс insignis , самый старый известный TherapsId». Журнал палеонтологии позвоночных . 16 (1): 95–102. Bibcode : 1996jvpal..16 ... 95L . doi : 10.1080/02724634.1996.10011287 .
- ^ Амсон, Эли; Лаурин, Мишель (2011). Ранние пермские синапсиды " Acta Poolonological Польша 56 (2): 301–312. doi : 10.4202/приложение . ISSN 0567-7920 . S2CID 56425905 .
- ^ Spindler, Frederik (2020). «Череп тетрацератопов отмечен (Synapsida, Sphenacodontia)». PalaeOvertebrata . 43 (1): E1. Doi : 10.18563 / pv.43.1.e1 . S2CID 214247325 .
- ^ Абдала, Фернандо; Рубидж, Брюс С.; Ван Ден Хивей, Юри (2008). «Самые старые тероцефалии (Therapsida, Eutheroidontia) и ранняя диверсификация Therapsida» . Палеонтология . 51 (4): 1011–1024. Bibcode : 2008Palgy..51.1011a . doi : 10.1111/j.1475-4983.2008.00784.x . ISSN 1475-4983 . S2CID 129791548 .
Дальнейшее чтение
[ редактировать ]- Бентон, MJ (2004). Палеонтология позвоночных , 3 -е изд., Blackwell Science.
- Кэрролл, Р.Л. (1988). Позвоночные палеонтология и эволюция . WH Freeman & Company, Нью -Йорк.
- Кемп, Т.С. (2005). Происхождение и эволюция млекопитающих . Издательство Оксфордского университета .
- Ромер, как (1966). Палеонтология позвоночных . Университет Чикагской Прессы, 1933; 3 -е изд.
- Bennett, AF, & Ruben, JA (1986). « Метаболический и терморегуляционный статус терапидов ». В экологии и биологии рептилий, подобных млекопитающим . Smithsonian Institution Press, Вашингтон, округ Колумбия, 207-218.
- Kammerer, CF, Angielczyk, KD, & Obisch, J. (2014). Ранняя эволюционная история синапсиды (2014 -е изд.). Спрингер Нидерланды. https://doi.org/10.1007/978-94-007-6841-3
- Росс, Р.П., Росс, Калифорния (2023). Пермский период, геохронология . Энциклопедия Британская. https://www.britannica.com/science/permian-period
- Падиан, Кевин (2013-09). «Обзор« предшественников млекопитающих: радиация, гистология, биология »». Журнал палеонтологии позвоночных . 33 (5): 1250–1251.
Внешние ссылки
[ редактировать ]
- " Therapsida: млекопитающие и вымершие родственники " Дерево жизни "
- " Therapsida: Opreview " Palaeos
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