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. 2021 Jul 9;11(1):14252.
doi: 10.1038/s41598-021-93808-2.

Temporomandibular joint and Giant Panda's (Ailuropoda melanoleuca) adaptation to bamboo diet

Pekka K Vallittu  1   2 , Juha Varrela  3   4 , Jukka Salo  5 , Li Rengui  6   7   8 , Ling Shanshan  6   7   8 , Huang Shan  6   7   8 , Hemin Zhang  6   7   8 , Pekka Niemelä  5
Affiliations

Temporomandibular joint and Giant Panda's (Ailuropoda melanoleuca) adaptation to bamboo diet

Pekka K Vallittu et al. Sci Rep. .

Abstract

Here, we present new evidence that evolutionary adaptation of the Ailuripodinae lineage to bamboo diet has taken place by morphological adaptations in the masticatory system. The giant panda in the wild and in captivity removes without an exception the outer skin of all bamboo shoots, rich in abrasive and toxic compounds, by the highly adapted premolars P3 and P4. The temporomandibular joint (TMJ) allows sidewise movement of the jaw and the premolars can, in a cusp-to-cusp position, remove the poorly digestible outer skin of the bamboo before crushing the bamboo with molars. Based on the evidence presented here, we suggest that adaptation of TMJ to lateral movement for enabling cusp-to-cusp contact of premolars is the crucial evolutionary factor as which we consider the key to understand the Ailuropodinae lineage adaptive pathway to utilize the bamboo resource.

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Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1
Figure 1
Occlusal view of the dentition showing three incisors, a canine, three premolars, and three molars in the mandible of giant panda. (A) Polar bear, (B) brown bear, (C) giant panda (old) and (D) giant panda (young). The white arrow shows the wear facet in the lower canine due to lateral movement of the jaw. Occlusally narrow (black arrows) P3 and P4 can slide the cusp-to-cups cutting position in lateral movement of the mandible.
Figure 2
Figure 2
Frontal view of the incisors and canine showed that the third incisor was larger than the other two incisors. Giant panda had the largest third incisors. (A) Polar bear, (B) brown bear, (C) giant panda (young) and (D) giant panda (old).
Figure 3
Figure 3
Condylar heads of the giant panda showed a widening of the lateral end with intercondylar angle of 180°. (A) Polar bear, (B) brown bear, (C) giant panda (young) and (D) giant panda (old).
Figure 4
Figure 4
Superimposed laser scans showed the lateral end of the condylar hear of giant panda to be a flat and widened surface. (A) Polar bear, (B) brown bear, (C) giant panda.
See this image and copyright information in PMC

References

    1. Nie J, Speakma JR, Wu Q, Zhang C, Hu Y, Xia M, Yan L, Hambly C, Wang L, Wei W, Zhang M, Wei F. Exceptionally low daily energy expenditure in the bamboo-eating giant panda. Science. 2015;349(10):171–174. doi: 10.1126/science.aab2413. - DOI - PubMed
    1. Schaller GB, Jinchu H, Wenshi P, Jing Z. The Giant Pandas of Wolong. University Chicago Press; 1985. p. 298.
    1. Long Y, Lü Z, Wang D, Zhu X, Wang H, Zhang Y, Pan W. Nutritional strategy of Giant Pandas in the Qingling Mountainsa of China. In: Lindburg D, Baragona K, editors. Giant Pandas—Biology and Conservation. University of California Press; 2004. pp. 90–100.
    1. Gittleman JL. Hanging bears from phylogenetic trees: Investigating patterns of macroevolution. Ursus. 1999;11:29–29.
    1. Jin C, Ciochon RL, Dong W, Hunt RM, Jinyi Liu K, Jaeger M, Zhu Q. The first skull of the earliest giant panda. Proc. Natl. Acad. Sci. 2007;104(26):10932–10937. doi: 10.1073/pnas.0704198104.PMC1904166.PMID17578912. - DOI - PMC - PubMed

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