Evidence map›Paper›PMID 42509587›Full record

ArticleAmerican journal of biological anthropology2026

A Systematic Revision of the Late Miocene Cercopithecid Monkeys From the Lemudong'o Formation, Kenya.

Julia L Arenson, Christopher C Gilbert, Deming Yang, Stanley H Ambrose, Rahab N Kinyanjui, Fredrick K Manthi, Erin N DiMaggio, Ashley S Hammond

Abstract read
In one paragraph

Article in American journal of biological anthropology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Julia L ArensonDepartment of Anthropology, Yale University, New Haven, Connecticut, USA.ORCID https://orcid.org/0000-0002-0956-7826
Christopher C GilbertDepartment of Anthropology, Hunter College of the City University of New York, New York, New York, USA.ORCID https://orcid.org/0000-0001-8768-3171
Deming YangDepartment of Anatomy, Midwestern University, Downers Grove, Illinois, USA.ORCID https://orcid.org/0000-0002-7719-6801
Stanley H AmbroseDepartment of Anthropology, University of Illinois, Urbana-Champaign, Urbana, Illinois, USA.ORCID https://orcid.org/0000-0002-8785-0512
Rahab N KinyanjuiDepartment of Earth Sciences, National Museums of Kenya, Nairobi, Kenya.ORCID https://orcid.org/0000-0003-2032-8321
Fredrick K ManthiDepartment of Earth Sciences, National Museums of Kenya, Nairobi, Kenya.
Erin N DiMaggioDepartment of Geosciences, Pennsylvania State University, University Park, Pennsylvania, USA.ORCID https://orcid.org/0000-0002-3157-5160
Ashley S HammondInstitut Català de Paleontologia Miquel Crusafont (ICP-CERCA), Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain.ORCID https://orcid.org/0000-0002-6657-1514

Funding

American Museum of Natural History Explore21 GrantAmerican Museum of Natural History Niarchos Expedition FundLeakey Foundation F202410582National Geographic SocietyNational Science Foundation 2018093National Science Foundation 2418990National Science Foundation 40F79-02 04National Science Foundation BCS-2418989
6 · The paper itself

Abstract

objectivesThe late Miocene Lemudong'o Formation in southwestern Kenya (6.2-6.0 Ma) samples an important period in Africa when early representatives of modern catarrhine clades (Hominidae and Cercopithecidae) appear. Fossils collected from this formation before 2007 include three species of colobine monkey. However, several new fossils have been recovered, including a partial cranium, calling for a reassessment of Lemudong'o Formation cercopithecid taxonomy. MATERIALS AND

methodsThis study describes 79 new cercopithecid specimens from collection years 2007-2016 and 2019-2024. These specimens, together with previously published material from the Lemudong'o Formation, are compared to fossil cercopithecids from other contemporaneous sites in Africa as well as a sample of extant cercopithecids.

resultsNew material supports the presence of the three previously identified colobine taxa and identifies a novel fourth colobine species. The novel colobine species is described as Olotimcolobus narokensis gen. et sp. nov., and the previously recognized small indeterminate colobine is here named Lemucolobus orkimusei gen. et sp. nov. Existing hypodigms are refined in light of this new taxonomy. A papionin is also identified from this formation for the first time, adding to the scant late Miocene cercopithecine record. DISCUSSION: The Lemudong'o Formation is remarkable for its high cercopithecid diversity in the Late Miocene. The predominance of colobines here and at other contemporaneous sites (e.g., Lukeino, Lothagam, Nakali, Toros Menalla) suggests that colobines were more diverse than cercopithecines through the early part of their radiation. Possible ecological factors are discussed in the context of early cercopithecid diversity and evolution.

Indexed as

CercopithecidaeFossilsAnimalsBiological EvolutionKenyaPhylogenySkullCercopithecinaeColobinaeeastern Africaprimate evolutiontaxonomy

Identifiers

PMID42509587
PMCPMC13408180

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.