晚白垩世真兽类Zalamdalestes揭示哺乳动物独特的枢椎及其复杂的进化过程  

The Late Cretaceous eutherian Zalambdalestes reveals unique axis and complex evolution of the mammalian neck

作　　者：Patrick Arnold Katarzyna Janiszewska 李茜 Jingmai K.O'Connor Lucja Fostowicz-Frelik Patrick Arnold;Katarzyna Janiszewska;Qian Li;Jingmai K.O’Connor;Łucja Fostowicz-Frelik(Institute of Biochemistry and Biology,University of Potsdam,Potsdam D-14476,Germany;Environmental Paleobiology Department,Institute of Paleobiology,Polish Academy of Sciences,Warsaw 00-818,Poland;Key Laboratory of Evolutionary Systematics of Vertebrates,Institute of Vertebrate Paleontology and Paleoanthropology,Chinese Academy of Sciences,Beijing 100044,China;The Field Museum of Natural History,Chicago IL 60605,USA;Department of Organismal Biology and Anatomy,The University of Chicago,Chicago IL 60637,USA;Evolutionary Paleobiology Department,Institute of Paleobiology,Polish Academy of Sciences,Warsaw 00-818,Poland)

机构地区：[1]Institute of Biochemistry and Biology,University of Potsdam,Potsdam D-14476,Germany [2]Environmental Paleobiology Department,Institute of Paleobiology,Polish Academy of Sciences,Warsaw 00-818,Poland [3]Key Laboratory of Evolutionary Systematics of Vertebrates,Institute of Vertebrate Paleontology and Paleoanthropology,Chinese Academy of Sciences,Beijing 100044,China [4]The Field Museum of Natural History,Chicago IL 60605,USA [5]Department of Organismal Biology and Anatomy,The University of Chicago,Chicago IL 60637,USA [6]Evolutionary Paleobiology Department,Institute of Paleobiology,Polish Academy of Sciences,Warsaw 00-818,Poland

出　　处：《Science Bulletin》2024年第11期1767-1775,共9页科学通报（英文版）

基　　金：supported by the National Science Centre(NCN,Kraków,Poland)(2015/18/E/NZ8/00637);the Polish National Agency for Academic Exchange(NAWA,Warszawa,Poland)(BPN/BEK/2021/1/00357/U/00001)to LFF。

摘　　要：The typical mammalian neck consisting of seven cervical vertebrae(C1–C7)was established by the Late Permian in the cynodont forerunners of modern mammals.This structure is precisely adapted to facilitate movements of the head during feeding,locomotion,predator evasion,and social interactions.Eutheria,the clade including crown placentals,has a fossil record extending back more than 125 million years revealing significant morphological diversification in the Mesozoic.Yet very little is known concerning the early evolution of eutherian cervical morphology and its functional adaptations.A specimen of Zalambdalestes lechei from the Late Cretaceous of Mongolia boasts exceptional preservation of an almost complete series of cervical vertebrae(C2–C7)revealing a highly modified axis(C2).The significance of this cervical morphology is explored utilizing an integrated approach combining comparative anatomical examination across mammals,muscle reconstruction,geometric morphometrics and virtual range of motion analysis.We compared the shape of the axis in Zalambdalestes to a dataset of 88 mammalian species(monotremes,marsupials,and placentals)using three-dimensional landmark analysis.The results indicate that the unique axis morphology of Zalambdalestes has no close analog among living mammals.Virtual range of motion analysis of the neck strongly implies Zalambdalestes was capable of exerting very forceful head movements and had a high degree of ventral flexion for an animal its size.These findings reveal unexpected complexity in the early evolution of the eutherian cervical morphology and suggest a feeding behavior similar to insectivores specialized in vermivory and defensive behaviors in Zalambdalestes akin to modern spiniferous mammals.

关 键 词：Atlas Axis Vertebral column Stem placental Morphology PALEOECOLOGY 

分 类 号：Q915[天文地球—古生物学与地层学]