{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T05:45:34Z","timestamp":1777873534911,"version":"3.51.4"},"reference-count":90,"publisher":"American Association for the Advancement of Science (AAAS)","issue":"6797","content-domain":{"domain":["www.science.org"],"crossmark-restriction":true},"short-container-title":["Science"],"published-print":{"date-parts":[[2026,4,30]]},"abstract":"<jats:p>The late Cenozoic period saw widespread diversification of grazing hoofed mammals characterized by high-crowned molar teeth with low, thinly enameled crests. However, Australia\u2019s dominant grazing herbivores, the kangaroos, have much lower-crowned and higher-relief molars that are more akin to some \u201carchaic\u201d placental herbivores. Using x-ray microcomputed tomography scanning, we show that as kangaroos shifted to higher-abrasion grazing diets, their ancestrally vertical, interlocking mode of occlusion favored the acquisition of thick enamel as a durability adaptation. Extant grass-feeding kangaroos have relatively much thicker molar enamel than browsing taxa, especially across the cutting lophs. Data from 41 fossil assemblages reveal a progressive increase in kangaroo enamel thickness from the Late Miocene that correlates with the expansion of arid Australian habitats. The evolutionary success of kangaroos reveals unappreciated contingency in herbivore adaptation and diversification.<\/jats:p>","DOI":"10.1126\/science.aeb2502","type":"journal-article","created":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T18:01:06Z","timestamp":1777572066000},"page":"488-492","update-policy":"https:\/\/doi.org\/10.34133\/aaas_crossmark","source":"Crossref","is-referenced-by-count":0,"title":["Contingent evolution of thick enamel by kangaroos to resist dietary abrasion"],"prefix":"10.1126","volume":"392","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5840-5412","authenticated-orcid":true,"given":"Aidan M. C.","family":"Couzens","sequence":"first","affiliation":[{"name":"College of Science &amp; Engineering, Flinders University, Adelaide, Australia."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9489-8274","authenticated-orcid":true,"given":"Benedict","family":"King","sequence":"additional","affiliation":[{"name":"Department of Linguistic and Cultural Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9958-0265","authenticated-orcid":true,"given":"Gavin J.","family":"Prideaux","sequence":"additional","affiliation":[{"name":"College of Science &amp; Engineering, Flinders University, Adelaide, Australia."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"221","reference":[{"key":"e_1_3_2_2_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1220872110"},{"key":"e_1_3_2_3_2","doi-asserted-by":"publisher","DOI":"10.1071\/AM90007"},{"key":"e_1_3_2_4_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1096-3642.2009.00607.x"},{"key":"e_1_3_2_5_2","doi-asserted-by":"publisher","DOI":"10.1111\/aec.12273"},{"key":"e_1_3_2_6_2","doi-asserted-by":"publisher","DOI":"10.1093\/icb\/icr028"},{"key":"e_1_3_2_7_2","first-page":"1","article-title":"Ungulate cheek teeth: Developmental, functional, and evolutionary interrelations","volume":"180","author":"Fortelius M.","year":"1985","unstructured":"M. Fortelius, Ungulate cheek teeth: Developmental, functional, and evolutionary interrelations. Acta Zool. Fenn. 180, 1\u201376 (1985).","journal-title":"Acta Zool. Fenn."},{"key":"e_1_3_2_8_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0508377102"},{"key":"e_1_3_2_9_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1469-185X.1988.tb00630.x"},{"key":"e_1_3_2_10_2","doi-asserted-by":"publisher","DOI":"10.1098\/rsfs.2015.0109"},{"key":"e_1_3_2_11_2","doi-asserted-by":"publisher","DOI":"10.1071\/ZO9800341"},{"key":"e_1_3_2_12_2","doi-asserted-by":"publisher","DOI":"10.5735\/086.051.0217"},{"key":"e_1_3_2_13_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.aas8788"},{"key":"e_1_3_2_14_2","doi-asserted-by":"publisher","DOI":"10.1038\/417538a"},{"key":"e_1_3_2_15_2","first-page":"599","article-title":"Evolution of manatees: A speculative history","volume":"56","author":"Domning D. P.","year":"1982","unstructured":"D. P. Domning, Evolution of manatees: A speculative history. J. Paleontol. 56, 599\u2013619 (1982).","journal-title":"J. Paleontol."},{"key":"e_1_3_2_16_2","doi-asserted-by":"publisher","DOI":"10.1038\/383068a0"},{"key":"e_1_3_2_17_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1815423116"},{"key":"e_1_3_2_18_2","doi-asserted-by":"publisher","DOI":"10.1146\/annurev-earth-072619-060126"},{"key":"e_1_3_2_19_2","unstructured":"A. M. C. Couzens PhD thesis Flinders University Adelaide Australia (2017)."},{"key":"e_1_3_2_20_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1109615108"},{"key":"e_1_3_2_21_2","doi-asserted-by":"publisher","DOI":"10.1071\/ZO02008"},{"key":"e_1_3_2_22_2","doi-asserted-by":"publisher","DOI":"10.1007\/s004420050869"},{"key":"e_1_3_2_23_2","doi-asserted-by":"publisher","DOI":"10.1146\/annurev-earth-031621-114105"},{"key":"e_1_3_2_24_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0028379"},{"key":"e_1_3_2_25_2","doi-asserted-by":"publisher","DOI":"10.1002\/bies.20729"},{"key":"e_1_3_2_26_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jhevol.2013.01.009"},{"key":"e_1_3_2_27_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jhevol.2007.09.014"},{"key":"e_1_3_2_28_2","first-page":"151","volume-title":"Kangaroos, Wallabies and Rat-Kangaroos","author":"Sanson G. D.","year":"1989","unstructured":"G. D. Sanson, \u201cMorphological adaptations of teeth to diets and feeding in the Macropodoidea\u201d in Kangaroos, Wallabies and Rat-Kangaroos, G. Grigg, P. J. Jarman, I. D. Hume, Eds. (Surrey Beatty & Sons, 1989), pp. 151\u2013168."},{"key":"e_1_3_2_29_2","doi-asserted-by":"publisher","DOI":"10.1002\/ajpa.1330550202"},{"key":"e_1_3_2_30_2","doi-asserted-by":"publisher","DOI":"10.5852\/cr-palevol2025v24a15"},{"key":"e_1_3_2_31_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.aaf8398"},{"key":"e_1_3_2_32_2","doi-asserted-by":"publisher","DOI":"10.1071\/BT04220"},{"key":"e_1_3_2_33_2","doi-asserted-by":"publisher","DOI":"10.1071\/BT11037"},{"key":"e_1_3_2_34_2","first-page":"453","article-title":"Correspondence between tooth shape and dietary biomechanical properties in insectivorous microchiropterans","volume":"7","author":"Evans A. R.","year":"2005","unstructured":"A. R. Evans, G. D. Sanson, Correspondence between tooth shape and dietary biomechanical properties in insectivorous microchiropterans. Evol. Ecol. Res. 7, 453\u2013478 (2005).","journal-title":"Evol. Ecol. Res."},{"key":"e_1_3_2_35_2","doi-asserted-by":"publisher","DOI":"10.1029\/2018GL077833"},{"key":"e_1_3_2_36_2","unstructured":"G. J. Prideaux paper presented at the 18th Conference on Australasian Vertebrate Evolution Palaeontology & Systematics (CAVEPS 2023) Melbourne Museum Victoria 27 to 30 November 2023."},{"key":"e_1_3_2_37_2","doi-asserted-by":"publisher","DOI":"10.1029\/2020GL090964"},{"key":"e_1_3_2_38_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.palaeo.2017.08.016"},{"key":"e_1_3_2_39_2","doi-asserted-by":"publisher","DOI":"10.24199\/j.mmv.2016.74.17"},{"key":"e_1_3_2_40_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0900956106"},{"key":"e_1_3_2_41_2","doi-asserted-by":"publisher","DOI":"10.11646\/zootaxa.5299.1.1"},{"key":"e_1_3_2_42_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.adq4340"},{"key":"e_1_3_2_43_2","doi-asserted-by":"publisher","DOI":"10.1017\/pab.2018.46"},{"key":"e_1_3_2_44_2","doi-asserted-by":"publisher","DOI":"10.1525\/california\/9780520098459.001.0001"},{"key":"e_1_3_2_45_2","doi-asserted-by":"publisher","DOI":"10.1080\/10292389209380421"},{"key":"e_1_3_2_46_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41559-023-02151-4"},{"key":"e_1_3_2_47_2","doi-asserted-by":"publisher","DOI":"10.2992\/0097-4463(2006)75[51:NBSAFT]2.0.CO;2"},{"key":"e_1_3_2_48_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-020-66425-8"},{"key":"e_1_3_2_49_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-023-41471-0"},{"key":"e_1_3_2_50_2","first-page":"367","article-title":"Phascolarctid origins and the potential of the selenodont molar in the evolution of diprotodont marsupials","volume":"17","author":"Archer M.","year":"1976","unstructured":"M. Archer, Phascolarctid origins and the potential of the selenodont molar in the evolution of diprotodont marsupials. Mem. Queensl. Mus. 17, 367\u2013371 (1976).","journal-title":"Mem. Queensl. Mus."},{"key":"e_1_3_2_51_2","doi-asserted-by":"publisher","DOI":"10.1017\/CBO9780511549717.008"},{"key":"e_1_3_2_52_2","doi-asserted-by":"publisher","DOI":"10.1007\/978-1-4613-9249-1_13"},{"key":"e_1_3_2_53_2","doi-asserted-by":"publisher","DOI":"10.1002\/ajpa.10353"},{"key":"e_1_3_2_54_2","doi-asserted-by":"publisher","DOI":"10.1537\/ase.050118"},{"key":"e_1_3_2_55_2","doi-asserted-by":"publisher","DOI":"10.1002\/ajpa.1330910405"},{"key":"e_1_3_2_56_2","doi-asserted-by":"publisher","DOI":"10.1186\/1751-0473-8-20"},{"key":"e_1_3_2_57_2","doi-asserted-by":"publisher","DOI":"10.1038\/314260a0"},{"key":"e_1_3_2_58_2","doi-asserted-by":"publisher","DOI":"10.1890\/02-9003"},{"key":"e_1_3_2_59_2","doi-asserted-by":"publisher","DOI":"10.1071\/ZO05077"},{"key":"e_1_3_2_60_2","doi-asserted-by":"publisher","DOI":"10.1006\/jhev.1996.0122"},{"key":"e_1_3_2_61_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jhevol.2008.08.004"},{"key":"e_1_3_2_62_2","doi-asserted-by":"publisher","DOI":"10.1007\/s10764-005-9004-1"},{"key":"e_1_3_2_63_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jhevol.2015.05.005"},{"key":"e_1_3_2_64_2","first-page":"96","article-title":"Energetic competition between Neandertals and anatomically modern humans","volume":"2009","author":"Froehle A. W.","year":"2009","unstructured":"A. W. Froehle, S. E. Churchill, Energetic competition between Neandertals and anatomically modern humans. Paleoanthropology 2009, 96\u2013116 (2009).","journal-title":"Paleoanthropology"},{"key":"e_1_3_2_65_2","doi-asserted-by":"publisher","DOI":"10.1098\/rsbl.2008.0223"},{"key":"e_1_3_2_66_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jhevol.2007.11.004"},{"key":"e_1_3_2_67_2","doi-asserted-by":"publisher","DOI":"10.1002\/evan.20251"},{"key":"e_1_3_2_68_2","doi-asserted-by":"publisher","DOI":"10.1093\/sysbio\/syy080"},{"key":"e_1_3_2_69_2","doi-asserted-by":"publisher","DOI":"10.1111\/2041-210X.12954"},{"key":"e_1_3_2_70_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0112705"},{"key":"e_1_3_2_71_2","doi-asserted-by":"publisher","DOI":"10.1093\/molbev\/msu176"},{"key":"e_1_3_2_72_2","doi-asserted-by":"publisher","DOI":"10.1093\/bioinformatics\/btg412"},{"key":"e_1_3_2_73_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.2041-210X.2011.00169.x"},{"key":"e_1_3_2_74_2","unstructured":"D. Orme R. Freckleton G. Thomas T. Petzoldt S. Fritz N. Isaac W. Pearse \u201ccaper: Comparative analyses of phylogenetics and evolution in R\u201d (R package version XXX 2013); https:\/\/cran.r-project.org\/web\/packages\/caper\/index.html."},{"key":"e_1_3_2_75_2","doi-asserted-by":"publisher","DOI":"10.1666\/09047.1"},{"key":"e_1_3_2_76_2","doi-asserted-by":"publisher","DOI":"10.1017\/CBO9780511529924.043"},{"key":"e_1_3_2_77_2","doi-asserted-by":"publisher","DOI":"10.1017\/CBO9780511529924.038"},{"key":"e_1_3_2_78_2","first-page":"260","volume-title":"Evolution of Tertiary Mammals of North America. Volume 1: Terrestrial Carnivores, Ungulates, and Ungulatelike Mammals","author":"Lucas S. G.","year":"1998","unstructured":"S. G. Lucas, \u201cTaeniodontia\u201d in Evolution of Tertiary Mammals of North America. Volume 1: Terrestrial Carnivores, Ungulates, and Ungulatelike Mammals, C. M. Janis, K. M. Scott, L. L. Jacobs, Eds. (Cambridge Univ. Press, 1998), pp. 260\u2013267."},{"key":"e_1_3_2_79_2","doi-asserted-by":"publisher","DOI":"10.1353\/book.485"},{"key":"e_1_3_2_80_2","first-page":"292","volume-title":"Evolution of Tertiary Mammals of North America. Volume 1: Terrestrial Carnivores, Ungulates, and Ungulatelike Mammals","author":"Archibald J. D.","year":"1998","unstructured":"J. D. Archibald, \u201cArchaic ungulates (\u201cCondylarthra\u201d)\u201d in Evolution of Tertiary Mammals of North America. Volume 1: Terrestrial Carnivores, Ungulates, and Ungulatelike Mammals, C. M. Janis, K. M. Scott, L. L. Jacobs, Eds. (Cambridge Univ. Press, 1998), pp. 292\u2013331."},{"key":"e_1_3_2_81_2","doi-asserted-by":"publisher","DOI":"10.1206\/3737.2"},{"key":"e_1_3_2_82_2","doi-asserted-by":"publisher","DOI":"10.1017\/CBO9780511529924.045"},{"key":"e_1_3_2_83_2","first-page":"53","article-title":"Hypsodonty in Pleistocene ground sloths","volume":"51","author":"Bargo M. S.","year":"2006","unstructured":"M. S. Bargo, G. De Luliis, S. F. Vizca\u00edno, Hypsodonty in Pleistocene ground sloths. Acta Palaeontol. Pol. 51, 53\u201361 (2006).","journal-title":"Acta Palaeontol. Pol."},{"key":"e_1_3_2_84_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1614029114"},{"key":"e_1_3_2_85_2","doi-asserted-by":"publisher","DOI":"10.1206\/3903.1"},{"key":"e_1_3_2_86_2","doi-asserted-by":"publisher","DOI":"10.1023\/A:1020500127041"},{"key":"e_1_3_2_87_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0200132"},{"key":"e_1_3_2_88_2","first-page":"37","article-title":"Neolicaphrium recens Frenguelli, 1921, the only surviving Proterotheriidae (Litopterna, Mammalia) into the south American Pleistocene","volume":"30","author":"Bond M.","year":"2001","unstructured":"M. Bond, D. Perea, M. Ubilla, A. Tauber, Neolicaphrium recens Frenguelli, 1921, the only surviving Proterotheriidae (Litopterna, Mammalia) into the south American Pleistocene. Palaeovertebrata 30, 37\u201350 (2001).","journal-title":"Palaeovertebrata"},{"key":"e_1_3_2_89_2","doi-asserted-by":"publisher","DOI":"10.1017\/CBO9780511529924.019"},{"key":"e_1_3_2_90_2","doi-asserted-by":"publisher","DOI":"10.1017\/CBO9780511529924.021"},{"key":"e_1_3_2_91_2","unstructured":"A. M. C. Couzens B. King G. J. Prideaux Data and code for: Contingent evolution of thick enamel by kangaroos to resist dietary abrasion Dryad (2026); https:\/\/doi.org\/10.5061\/dryad.4b8gthtmd."}],"container-title":["Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.science.org\/doi\/pdf\/10.1126\/science.aeb2502","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T18:01:35Z","timestamp":1777572095000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.science.org\/doi\/10.1126\/science.aeb2502"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,30]]},"references-count":90,"journal-issue":{"issue":"6797","published-print":{"date-parts":[[2026,4,30]]}},"alternative-id":["10.1126\/science.aeb2502"],"URL":"https:\/\/doi.org\/10.1126\/science.aeb2502","relation":{},"ISSN":["0036-8075","1095-9203"],"issn-type":[{"value":"0036-8075","type":"print"},{"value":"1095-9203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,30]]},"assertion":[{"value":"2025-08-08","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-03-09","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-04-30","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}