Editing Mussaurus (section)

==Palaeobiology==
[[File:Mussaurus patagonicus.jpg|thumb|Life restoration of an infant eating a ''[[Dicroidium]]'' fern]]
''Mussaurus'' specimens have been found in association with nests that are believed to contain multiple eggs apiece. The skeletons of ''Mussaurus'' infants were small, measuring about {{convert|20|cm|in}} long and weighing about {{convert|53.3|-|76.5|g|oz}}.<ref>{{cite book|last1=Holtz|first1=T. R.|last2=Rey|first2=L. V.|title=Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages|date=2007|publisher=Random House}} [https://www.geol.umd.edu/~tholtz/dinoappendix/HoltzappendixWinter2011.pdf Supplementary Information 2012]  [https://www.geol.umd.edu/~tholtz/dinoappendix/appendix.html Weight Information]</ref><ref name=OCAS19/> This is about the size of a small lizard. Juveniles differed from adults in proportion in addition to size and mass. As is common for dinosaurs, juvenile ''Mussaurus'' had tall skulls with short snouts and large eyes. These proportions are common in many infant vertebrates and are often associated with species that provide parental care during the vulnerable early stages of life. Adults are expected to have longer snouts and necks, as typical in early [[sauropodomorph]]s.<ref name=ageofdinosaursmussaurus/> Ignacio Cerda and Diego Pol reported putative evidence of medullary bone tissue from a specimen of ''Mussaurus'' in 2013,<ref>{{cite journal|author1=Cerda I.A.|author2=Pol, D.|year=2013|title=Evidence for gender-specific reproductive tissue in a basal sauropodomorph dinosaur from the Late Triassic of Argentina|journal=Ameghiniana|volume=50|pages=11–12R}}</ref> but both authors with Anusuya Chinsamy subsequently argued in 2014 that this tissue most likely represents a pathologically formed tissue instead based on histological features.<ref>{{cite journal|author1=Cerda, I.A.|author2=Chinsamy, A.|author3=Pol, D.|year=2014|title=Unusual Endosteally Formed Bone Tissue in a Patagonian Basal Sauropodomorph Dinosaur|journal=The Anatomical Record|volume=297|issue=8|pages=1385–1391|doi=10.1002/ar.22954|pmid=24863550 |hdl=11336/16721|hdl-access=free}}</ref>

===Social behaviour===
As of 2021, ''Mussaurus'' represents the earliest unequivocal evidence of complex social behaviour in dinosaurs, with over 100 eggs and skeletal specimens of 80 individuals ranging from embryos to adults found in the same locality. This discovery predates the previous records of herd-living dinosaurs by at least 40 million years. It is thought that this behaviour has been originated from the Triassic period, leading them to become successful as large terrestrial herbivores.<ref name=Pol21/>

===Growth===
[[File:Mussaurus specimens.png|250px|thumb|right|Mussaurus specimens. (a,b) hatchling, (c) yearling, (d) adult. Scale bars represent 5 cm (a), (b) 15 cm (c) and 100 cm (d). To better show isolated bones in (c), we used specimen PVL 4587, of the same ontogenetic age as MPM 1813 (except for the ilium, which belongs to MPM 1813). ]]
A study published in May 2019 shows that in its first year of life, during which it weighed {{convert|6.5|-|10.2|kg|lb}}, ''M. patagonicus'' probably a was [[quadrupedalism|quadruped]], walking on all four limbs. Changes in the relative proportions of its body during growth ([[ontogeny]]) may have caused its [[centre of mass]] to move backwards towards its [[pelvis]], resulting in the animal adopting a two-legged ([[bipedalism|bipedal]]) stance later in life. Adult ''Mussaurus'' had a tail length of {{convert|3.13|m|ft}} and weighed up to {{convert|1.2|-|1.6|MT|ST}}, significantly larger than subadults which weighed about {{convert|106.2|-|557|kg|lb}}.<ref name=OCAS19>{{cite journal |last1=Otero |first1=Alejandro |last2=Cuff |first2=Andrew R. |last3=Allen |first3=Vivian |last4=Sumner-Rooney |first4=Lauren |last5=Pol |first5=Diego |last6=Hutchinson |first6=John R. |title=Ontogenetic changes in the body plan of the sauropodomorph dinosaur ''Mussaurus patagonicus'' reveal shifts of locomotor stance during growth |journal=Scientific Reports |publisher=Springer Science and Business Media LLC |volume=9 |issue=1 |date=2019-05-20 |issn=2045-2322 |doi=10.1038/s41598-019-44037-1 |page= 7614|pmid=31110190 |pmc=6527699|bibcode=2019NatSR...9.7614O }} [https://static-content.springer.com/esm/art%3A10.1038%2Fs41598-019-44037-1/MediaObjects/41598_2019_44037_MOESM1_ESM.pdf Supplementary Information]</ref><ref name=Pol21/> Individuals of such size would have measured up to {{convert|8|m|ft}} in total body length.<ref>{{Cite book|last=Paul|first=Gregory S.|url=http://worldcat.org/oclc/985402380|title=The Princeton Field Guide to Dinosaurs|year=2016|publisher=Princeton University Press|isbn=978-1-78684-190-2|oclc=985402380|pages=192}}</ref> It is estimated that ''Mussaurus'' would have been sexually mature at 23 to 31 years of age, and reached somatic maturity after 14 years.<ref>{{cite journal|author=Ignacio A. Cerda, Diego Pol, Alejandro Otero & Anusuya Chinsamy|year=2022|title=Palaeobiology of the early sauropodomorph Mussaurus patagonicus inferred from its long bone histology|journal=Palaeontology|volume=65|issue=4|at=e12614|doi=10.1111/pala.12614|s2cid=251181122 |doi-access=free|bibcode=2022Palgy..6512614C }}</ref>