PT  - JOURNAL ARTICLE
AU  - Jin Meng
AU  - Fangyuan Mao
TI  - Monotreme middle ear is not primitive for Mammalia
AID  - 10.1101/2021.05.03.442467
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.05.03.442467
4099  - http://biorxiv.org/content/early/2021/05/05/2021.05.03.442467.short
4100  - http://biorxiv.org/content/early/2021/05/05/2021.05.03.442467.full
AB  - The study on evolution of the mammalian middle ear has been fueled by continuous discoveries of Mesozoic fossils in the last two decades. Wang et al.1 recently reported a specimen of Vilevolodon diplomylos (IMMNH-PV01699)2 that adds to the increasing knowledge about the auditory apparatus of ‘haramiyidans’, an extinct Mesozoic group of mammaliaforms. The authors hypothesized that a middle ear with a monotreme-like incus and malleus and incudomallear articulation was primitive for mammals, which challenges the convention that the monotreme middle ear is specialized3 or autapomorphic4 in mammals. We raise concerns about terminology and identification of the incus presented by Wang et al. and show that their analysis does not support their hypothesis; instead, it supports the one by Mao et al.5,6.Competing Interest StatementThe authors have declared no competing interest.