Editing Mylodon (section)

=== Locomotion ===
In general, large mylodonts are ground-dwelling animals. The lower section of the hind leg, which is very short compared to the upper, is also found in ''Mylodon'', whose tibia is 27 cm in length and only half as long as the thigh bone, 59 cm in length. In comparison, the Megatheriidae possess significantly longer lower leg portions, about the almost equally-proportioned ''[[Pyramiodontherium]]'' possessing to a 47 cm long shin to a 49 cm long femur. Possibly these differences in the hind leg structure result in much more agile locomotion in the Megatheria in relation to the mylodonts.<ref name="deiuliisetal2004">{{cite journal |last1=De Iuliis |first1=Gerardo |last2=Ré |first2=Guillermo H. |last3=Vizcaíno |first3=Sergio F. |title=The Toro Negro megatheriine (Mammalia, Xenarthra): a new species of Pyramiodontherium and a review of Plesiomegatherium |journal=Journal of Vertebrate Paleontology |date=25 March 2004 |volume=24 |issue=1 |pages=214–227 |doi=10.1671/17.1 |bibcode=2004JVPal..24..214D |s2cid=85178982 }}</ref> Similar to other large ground sloths, the hand of ''Mylodon'' made contact with the ground with the outer side edge and thus sat up rotated. This is indicated by the long metacarpal bones of the external digits and the decreasing number of phalanges on them. The special hand position protected the long claws of the inner digits, which did not penetrate the ground while walking. A functionally similar but fundamentally different hand position can be found in the ankle duct of the distantly related present-day great anteater. The elbow joint was pointed slightly outwards when standing on four feet and the arms were thus angled slightly inwards, which is evident from the position of the olecranon yields. The hands came to rest slightly within the width of the elbow. Such an orientation of the arms can effectively support the large mass of ''Mylodon''. As a result, the hands would also be in a line with the feet, which is also conveyed, among other things, by footprints from ''Paramylodon''. The laterally limited articular surface of the femoral head severely restricted the mobility of the hindlimbs. The same applies to the forearm, the straight spoke with the laterally elongated head of which did not allow any major rotational movements. These features can be interpreted as adaptations to a purely [[terrestrial animal|terrestrial]] lifestyle. Finally, the muscle attachment points on the first cervical vertebra referenced, which are more developed than for example with ''Paramylodon''. Correspondingly, the occipital joint surfaces are also somewhat further apart. Both can be interpreted as meaning that the more massive skull of ''Mylodon'', caused by the lengthening of the snout region, required greater muscle support.<ref name="kraglievich1934"/><ref name="mcafee2016"/>

For some of the mylodonts of South America, such as ''Glossotherium'', a partially burrowing way of life is being reconstructed, which results from the construction of the foreleg, among other things. An indicator for this is the upper articular process (olecranon) of the ulna. The longer the olecranon, the higher the leverage of the forearm, since more attachment surface is available for the forearm muscles. In ''Glossotherium'', the olecranon takes up up to 35% of the total length of the ulna. The resulting ability to dig would be comparable to that of the ''[[Tolypeutes]]'' armadillos, which seldom build their own burrows, but can do so.<ref name="bargoetal2000">{{cite journal |last1=Bargo |first1=M. Susana |last2=Vizcaíno |first2=Sergio F. |last3=Archuby |first3=Fernando M. |last4=Blanco |first4=R. Ernesto |title=Limb bone proportions, strength and digging in some Lujanian (Late Pleistocene-Early Holocene) mylodontid ground sloths (Mammalia, Xenarthra) |journal=Journal of Vertebrate Paleontology |date=25 September 2000 |volume=20 |issue=3 |pages=601–610 |doi=10.1671/0272-4634(2000)020[0601:LBPSAD]2.0.CO;2 |s2cid=86036390 }}</ref> The previous analyses for ''Mylodon'' resulted in a much shorter olecranon, which accounts for only about 22% of the total length of the ulna. However, the fact that proportional estimates for ''Mylodon'' refer to a not fully grown specimen is problematic.<ref name="haroetal2016">{{cite journal |last1=Haro |first1=José A. |last2=Tauber |first2=Adan A. |last3=Krapovickas |first3=Jerónimo M. |title=The manus of mylodon darwinii Owen (Tardigrada, Mylodontidae) and its phylogenetic implications |journal=Journal of Vertebrate Paleontology |date=2 September 2016 |volume=36 |issue=5 |pages=e1188824 |doi=10.1080/02724634.2016.1188824 |bibcode=2016JVPal..36E8824H |s2cid=89036115 |url=https://figshare.com/articles/dataset/The_manus_of_i_Mylodon_darwinii_i_Owen_Tardigrada_Mylodontidae_and_its_phylogenetic_implications/3443405 |hdl=11336/179728 |hdl-access=free }}</ref> Other clues can be derived from the construction of the hand. In ''Mylodon'', for example, the metacarpal bones of the second and third ray are very delicate, in contrast to ''Glossotherium''. A weakly pronounced central ray does not seem to support a digging activity, as this is usually most strongly developed in underground mammals. However, the distal articular facet of the third metacarpal bone is flat, which means that the middle finger is generally stiff and stable. The same articulation surface on the second metacarpal is significantly more rounded and thus supports greater mobility of the finger when gripping. This obviously resulted in functional differences between the individual rays of the hand. The rare signs of wear and tear on the last phalanx, which are isolated from the Cueva del Milodón several times, can serve as an additional indicator of digging activities.<ref name="mcafee2016"/><ref name="haroetal2016"/>