冈瓦那兽目

冈瓦那兽目 化石时期： 坎帕阶-中新世, （可能在侏罗纪出现）
科学分类
界： 动物界 Animalia 门： 脊索动物门 Chordata 亚门： 脊椎动物亚门 Vertebrata 纲： 哺乳纲 Mammalia 目： 冈瓦那兽目 Gondwanatheria
科
?Allostaffia科 Sudamericidae科 Bharattherium Gondwanatherium Lavanify Patagonia Sudamerica Vintana Ferugliotheriidae科 Ferugliotherium Trapalcotherium (?) Argentodites †Groeberiidae科 †Groeberia ?†Klohnia ?†Epiklohnia ?†Praedens 未知的科 Greniodon

冈瓦那兽目（学名：Gondwanatheria，亦可称为冈瓦纳兽目）是哺乳动物中一个已经灭绝的目，生活在上白垩世至中新世（而且可能更早，如果将Allostaffia划为该目的成员）的南半球，包括南极洲。该类群为人所知的仅有数颗分离的牙齿，几片下颌骨，两块不完整的头骨和一个完整的头盖骨。 正是因为这种零碎的知识，其分类地位不甚清晰。

分类

Vintana sertichi的复原图。除头部外的身体部分为想象。

该类群分类关系的不明确持续了几十年，其最开始被认为是早期的异关节总目动物，一种“无齿”的哺乳动物，接近现代的食蚁兽。随后的多个不同研究认为它们属于异兽亚纲，接近多瘤齿兽目，甚至可能真正属于多瘤齿兽目，比Cimolodonta亚目更接近于Plagiaulacida亚目。然而，一项最近的研究表明，它们与贼兽目有关，并将它们列入非哺乳动物的犬齿兽亚目。

冈瓦那兽目下有3个已知的科，其中Sudamericidae科由Scillato-Yané及Pascual于1984年命名，包含该类群的绝大多数部分。Ferugliotheriidae科由José Bonaparte于1986年命名, 包含Ferugliotherium一个属，而且可能包括诸如Trapalcotherium等其他类群。Groeberiidae科最开始被认为是paucituberculate科的有袋类，之后由于该科中Groeberia属经检验被归入冈瓦那兽目，所以整个科也被归入冈瓦那兽目。

Gondwanatheria cladogram per Chimento et al. 2015.

另有化石在印度、马达加斯加、南极被发现。一个可能为Ferugliotherium属的物种在墨西哥的马斯特里赫特期地层中被发现，使得此类群的分布范围扩展到北美洲。

The Miocene (Colhuehuapian) genus Patagonia is the youngest known representative.

生物学

Gondwanatheres known from cranial remains almost universally have deep, robust snouts, as befitting their specialised herbivorous lifestyle. Groeberia and Vintana both possess bizarre jugal flanges similar to those of xenarthrans like ground sloths, though they had a palinal (front-to-back) chewing method as in most allotheres and unlike almost any therian. Most gondwanatheres are specialised grazers, even being among the first mammals to have specialised for grass-eating long before any therians did, with the exceptions of Groeberidae and Ferugliotheriidae, which lack hyopsodont teeth and therefore had more generalistic herbivorous habits.

An articulated specimen found in the Maevarano Formation offers insight to the postcranial skeleton of these animals. Among the bizarre and unique features are a mediolaterally compressed and antero-posteriorly bowed tibia, a double trochlea on the astragalus, a fully developed humeral trochlea, and an unusually high number of trunk vertebrae. The new taxon has at least 19 rib-bearing (thoracic) and 11 non-rib-bearing (lumbar) vertebrae. Aside from these derived features, the Malagasy mammal has a mosaic pectoral girdle morphology: the procoracoid is lost, the coracoid is extremely well developed (into an enlarged process that contributes to half of the glenoid fossa), the interclavicle is small, and the sternoclavicular joint appears mobile. A ventrally facing glenoid and the well-developed humeral trochlea suggest a relatively parasagittal posture for the forelimbs. Remarkable features of the hind limb and pelvic girdle include a large obturator foramen similar in size to that of therians, a large parafibula, and the presence of an epipubic bone.

分类

Order †Gondwanatheria McKenna 1971 [Gondwanatheroidea Krause & Bonaparte 1993]

• ?†Allostaffia
• Family †Groeberiidae Patterson, 1952
  • †Groeberia minoprioi Ryan Patterson, 1952
  • †Groeberia pattersoni G. G. Simpson, 1970
  • ?†Klohnia charrieri Flynn & Wyss 1999
  • ?†Klohnia major Goin et all 2010
  • ?†Epiklohnia verticalis Goin et all 2010
  • ?†Praedens aberrans Goin et all 2010
• Family †Ferugliotheriidae Bonaparte 1986
  • †Ferugliotherium windhauseni Bonaparte 1986a [Vucetichia Bonaparte 1990; Vucetichia gracilis Bonaparte 1990]
  • †Trapalcotherium matuastensis Rougier et al. 2008
• Family †Sudamericidae Scillato-Yané & Pascual 1984 [Gondwanatheridae Bonaparte 1986]
  • †Greniodon sylvanicum Goin et al. 2012
  • †Vintana sertichi Krause et al. 2014
  • †Dakshina jederi Wilson, Das Sarama & Anantharaman 2007
  • †Gondwanatherium patagonicum Bonaparte 1986
  • †Sudamerica ameghinoi Scillato-Yané & Pascual 1984
  • †Lavanify miolaka Krause et al. 1997
  • †Bharattherium bonapartei Prasad et al. 2007
  • †Patagonia peregrina Pascual & Carlini 1987
  • †TNM 02067

外部联系

• Mesozoic Mammals - Gondwanatheria