Conservation of placentation during the tertiary radiation of mammals in South America

Anthony Michael Carter, Andrea Maria Mess

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

The eutherian placenta is considered to possess great plasticity, but it is not clear how this variation reflects adaptation to different ecological niches. Because South America was isolated for most of the Tertiary, it represents a natural laboratory to examine this question. We here describe placentation in three South American groups: Xenarthra have been part of the fauna from at least the mid-Paleocene whereas caviomorph rodents and Neotropical primates are each derived from a single founder that reached South America in the Eocene and Oligocene, respectively. The common ancestor of Xenarthra had a villous, haemochorial placenta, from which the labyrinthine, endotheliochorial placenta of sloths later evolved. Placentation in Caviomorpha follows an extraordinary stable pattern, characterized by a haemomonochorial, labyrinthine and highly lobed structure with specialized growing areas. This pattern was present before arrival of these rodents in South America and enabled a successful radiation especially during the spread of grasslands. Neotropical primates have haemochorial, trabecular placentas with a specialized maternal blood supply; a pattern that contrasts with that of Old World monkeys and may have been present in the founder generation on arrival in South America. In conclusion, there is a dichotomy within Xenarthra but otherwise the ancient South American mammals do not show much variation in principal placental characters. Thus, the successful radiation of these three groups, and their adaptation to diverse ecological niches, did not require substantial alterations in placentation. J. Morphol., 2013. © 2013 Wiley Periodicals, Inc.
OriginalsprogEngelsk
TidsskriftJournal of Morphology
Vol/bind274
Udgave nummer5
Sider (fra-til)557–569
ISSN0362-2525
DOI
StatusUdgivet - 2013

Fingeraftryk

Placentation
Xenarthra
placenta
Placenta
Mammals
mammals
Primates
Rodentia
Sloths
niches
rodents
Cercopithecidae
ancestry
grasslands
Mothers
fauna
blood

Citer dette

@article{cfaf10e81815429e8272ecd0044886a0,
title = "Conservation of placentation during the tertiary radiation of mammals in South America",
abstract = "The eutherian placenta is considered to possess great plasticity, but it is not clear how this variation reflects adaptation to different ecological niches. Because South America was isolated for most of the Tertiary, it represents a natural laboratory to examine this question. We here describe placentation in three South American groups: Xenarthra have been part of the fauna from at least the mid-Paleocene whereas caviomorph rodents and Neotropical primates are each derived from a single founder that reached South America in the Eocene and Oligocene, respectively. The common ancestor of Xenarthra had a villous, haemochorial placenta, from which the labyrinthine, endotheliochorial placenta of sloths later evolved. Placentation in Caviomorpha follows an extraordinary stable pattern, characterized by a haemomonochorial, labyrinthine and highly lobed structure with specialized growing areas. This pattern was present before arrival of these rodents in South America and enabled a successful radiation especially during the spread of grasslands. Neotropical primates have haemochorial, trabecular placentas with a specialized maternal blood supply; a pattern that contrasts with that of Old World monkeys and may have been present in the founder generation on arrival in South America. In conclusion, there is a dichotomy within Xenarthra but otherwise the ancient South American mammals do not show much variation in principal placental characters. Thus, the successful radiation of these three groups, and their adaptation to diverse ecological niches, did not require substantial alterations in placentation. J. Morphol., 2013. {\circledC} 2013 Wiley Periodicals, Inc.",
author = "Carter, {Anthony Michael} and Mess, {Andrea Maria}",
note = "Copyright {\circledC} 2013 Wiley Periodicals, Inc.",
year = "2013",
doi = "10.1002/jmor.20120",
language = "English",
volume = "274",
pages = "557–569",
journal = "Journal of Morphology",
issn = "0362-2525",
publisher = "JohnWiley & Sons, Inc.",
number = "5",

}

Conservation of placentation during the tertiary radiation of mammals in South America. / Carter, Anthony Michael; Mess, Andrea Maria.

I: Journal of Morphology, Bind 274, Nr. 5, 2013, s. 557–569.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Conservation of placentation during the tertiary radiation of mammals in South America

AU - Carter, Anthony Michael

AU - Mess, Andrea Maria

N1 - Copyright © 2013 Wiley Periodicals, Inc.

PY - 2013

Y1 - 2013

N2 - The eutherian placenta is considered to possess great plasticity, but it is not clear how this variation reflects adaptation to different ecological niches. Because South America was isolated for most of the Tertiary, it represents a natural laboratory to examine this question. We here describe placentation in three South American groups: Xenarthra have been part of the fauna from at least the mid-Paleocene whereas caviomorph rodents and Neotropical primates are each derived from a single founder that reached South America in the Eocene and Oligocene, respectively. The common ancestor of Xenarthra had a villous, haemochorial placenta, from which the labyrinthine, endotheliochorial placenta of sloths later evolved. Placentation in Caviomorpha follows an extraordinary stable pattern, characterized by a haemomonochorial, labyrinthine and highly lobed structure with specialized growing areas. This pattern was present before arrival of these rodents in South America and enabled a successful radiation especially during the spread of grasslands. Neotropical primates have haemochorial, trabecular placentas with a specialized maternal blood supply; a pattern that contrasts with that of Old World monkeys and may have been present in the founder generation on arrival in South America. In conclusion, there is a dichotomy within Xenarthra but otherwise the ancient South American mammals do not show much variation in principal placental characters. Thus, the successful radiation of these three groups, and their adaptation to diverse ecological niches, did not require substantial alterations in placentation. J. Morphol., 2013. © 2013 Wiley Periodicals, Inc.

AB - The eutherian placenta is considered to possess great plasticity, but it is not clear how this variation reflects adaptation to different ecological niches. Because South America was isolated for most of the Tertiary, it represents a natural laboratory to examine this question. We here describe placentation in three South American groups: Xenarthra have been part of the fauna from at least the mid-Paleocene whereas caviomorph rodents and Neotropical primates are each derived from a single founder that reached South America in the Eocene and Oligocene, respectively. The common ancestor of Xenarthra had a villous, haemochorial placenta, from which the labyrinthine, endotheliochorial placenta of sloths later evolved. Placentation in Caviomorpha follows an extraordinary stable pattern, characterized by a haemomonochorial, labyrinthine and highly lobed structure with specialized growing areas. This pattern was present before arrival of these rodents in South America and enabled a successful radiation especially during the spread of grasslands. Neotropical primates have haemochorial, trabecular placentas with a specialized maternal blood supply; a pattern that contrasts with that of Old World monkeys and may have been present in the founder generation on arrival in South America. In conclusion, there is a dichotomy within Xenarthra but otherwise the ancient South American mammals do not show much variation in principal placental characters. Thus, the successful radiation of these three groups, and their adaptation to diverse ecological niches, did not require substantial alterations in placentation. J. Morphol., 2013. © 2013 Wiley Periodicals, Inc.

U2 - 10.1002/jmor.20120

DO - 10.1002/jmor.20120

M3 - Journal article

VL - 274

SP - 557

EP - 569

JO - Journal of Morphology

JF - Journal of Morphology

SN - 0362-2525

IS - 5

ER -