# Multilocus Phylogeny of Asiatic Striped Squirrels (Sciuridae, Tamiops) Reveals Their Evolutionary Relationships and Species Limits

## TL;DR

This study uses genetic data to reveal that the genus Tamiops contains seven distinct species, including a newly elevated species, and shows their evolutionary history spans over 13 million years.

## Contribution

The study provides the first multi-locus phylogeny of Tamiops, revealing hidden species diversity and clarifying evolutionary relationships.

## Key findings

- Seven well-supported monophyletic clades were identified within Tamiops using nuclear and mitochondrial data.
- T. maritimus hainanus was elevated to full species status based on genetic divergence of 6.01 million years.
- Divergence within the genus Tamiops began approximately 13.3 million years ago.

## Abstract

The genus Tamiops, classified within the family Sciuridae and the subfamily Callosciurinae, is distributed across East and Southeast Asia. The taxonomic classification of Tamiops has historically been contentious, with species diversity often underestimated due to reliance on pelage color variations for species descriptions, which are thought to reflect seasonal changes. To clarify the internal phylogenetic relationships and taxonomic status of the Tamiops species, we conducted morphological analyses and constructed multi‐locus phylogenetic trees using a large DNA dataset that encompassed one mitochondrial locus (Cyt‐b) and three nuclear loci (IRBP, PRKCI, RAG1), as well as 20 complete mitochondrial genomes. We identified seven well‐supported monophyletic clades of Tamiops based nuclear data evidence. The K2P genetic distances among the seven lineages of Tamiops varied from 0.095 to 0.204. Consequently, we elevated one subspecies—

T. maritimus hainanus

—to full species status, having diverged from its common ancestor approximately 6.01 million years ago. Ultimately, we recognized a total of seven valid species within the genus Tamiops, which include
T. swinhoei
,
T. maritimus
, T. hainanus,
T. barbei
, T. roldolphii, T. minshanica, and
T. mcclellandii
. Divergence time estimation suggested that Tamiops began to diversify approximately 13.3 million years ago (Mya). Our findings provide insights into the evolutionary relationships and previously overlooked species diversity within the genus Tamiops.

The genus Tamiops has long been underestimated in terms of species diversity due to reliance on seasonal fur coloration. This study integrates mitochondrial whole‐genome and nuclear gene data to identify seven monophyletic lineages, elevating
T. maritimus hainanus
to independent species status. Furthermore, it infers that divergence within the genus began approximately 13.3 million years ago, revealing its hidden diversity.