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Medientyp:
E-Artikel
Titel:
Human‐like enamel growth in Homo naledi
Beteiligte:
Mahoney, Patrick;
McFarlane, Gina;
Taurozzi, Alberto J.;
Madupe, Palesa P.;
O'Hara, Mackie C.;
Molopyane, Keneiloe;
Cappellini, Enrico;
Hawks, John;
Skinner, Matthew M.;
Berger, Lee
Erschienen:
Wiley, 2024
Erschienen in:American Journal of Biological Anthropology
Sprache:
Englisch
DOI:
10.1002/ajpa.24893
ISSN:
2692-7691
Entstehung:
Anmerkungen:
Beschreibung:
<jats:title>Abstract</jats:title><jats:sec><jats:title>Objectives</jats:title><jats:p>A modern pattern (rate and duration) of dental development occurs relatively recently during human evolution. Given the temporal overlap of <jats:italic>Homo</jats:italic> <jats:italic>naledi</jats:italic> with the first appearance of fossil <jats:italic>Homo sapiens</jats:italic> in Africa, this small‐bodied and small‐brained hominin presents an opportunity to elucidate the evolution of enamel growth in the hominin clade. Here we conduct the first histological study of two permanent mandibular canines and one permanent maxillary first molar, representing three individuals attributed to <jats:italic>H</jats:italic>. <jats:italic>naledi</jats:italic>. We reconstruct the rate and duration of enamel growth and compare these findings to those reported for other fossil hominins and recent humans.</jats:p></jats:sec><jats:sec><jats:title>Materials and Methods</jats:title><jats:p>Thin sections of each tooth were produced using standard histological methods. Daily and longer period incremental markings were measured to reconstruct enamel secretion and extension rates, Retzius periodicity, canine crown and molar cusp formation time.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Daily enamel secretion rates overlapped with those from recent hominins. Canine crown formation time is similar to that observed in recent Europeans but is longer than canine formation times reported for most other hominins including <jats:italic>Australopithecus</jats:italic> and <jats:italic>H. neanderthalensis</jats:italic>. The extended period of canine formation appears to be due to a relatively tall enamel crown and a sustained slow rate of enamel extension in the cervical portion of the crown. A Retzius periodicity of 11 days for the canines, and nine days for the molar, in <jats:italic>H</jats:italic>. <jats:italic>naledi</jats:italic> parallel results found in recent humans. An 11‐day periodicity has not been reported for Late Pleistocene <jats:italic>Homo</jats:italic> (<jats:italic>H. erectus</jats:italic>, <jats:italic>H. neanderthalensis</jats:italic>) and is rarely found in <jats:italic>Australopithecus</jats:italic> and <jats:italic>Paranthropus</jats:italic> species.</jats:p></jats:sec><jats:sec><jats:title>Discussion</jats:title><jats:p>Enamel growth of <jats:italic>H</jats:italic>. <jats:italic>naledi</jats:italic> is most similar to recent humans though comparative data are limited for most fossil hominin species. The high Retzius periodicity values do not follow expectations for a small‐brained hominin.</jats:p></jats:sec>