Caatinga Laucha

Open encyclopedia reference

The caatinga vesper mouse (Calomys expulsus) (also known as the caatinga laucha or rejected vesper mouse) is a rodent species in the family Cricetidae from South America. It is endemic to eastern Brazil, where it is found in open savanna (cerrado) and thorny scrub (caatinga) habitats. Its karyotype has 2n = 66 and FN = 68. It was formerly synonymized with C. callosus, but the latter has 2n = 50 and FN = 66. Karyologic analysis of C. expulsus has shown that the X chromosome is large and submetacentric while the Y chromosome is either acrocentric or submetacentric. Predators include the barn owl . Sexual dimorphism in shape and size occurs; the former is present mainly before the age of 20 days. Males are smaller before age 50 days and larger thereafter, which becomes less prominent after 200 days.

Wikipedia contributors, Caatinga vesper mouse; see linked history · CC BY-SA 4.0 . Plain-text lead excerpt, at most 180 words; no infobox or later sections Retrieved 2026-10-05T04:24:36.389865+00:00. This reference remains separate from the taxonomic record.

Identity & source status

Scientific name

Calomys expulsus (Lund, 1841)

Name authority

(Lund, 1841)

Common name

Caatinga Laucha

Rank

species

Accepted status

accepted

Kingdom

Animalia

Phylum

Chordata

Class

Mammalia

Order

Rodentia

Family

Cricetidae

Genus

Calomys

Extinction status

Recorded extant

Classification family tree

Nested taxonomic groups from the source. This is not a direct-ancestor chain, a dated evolutionary tree or a phylogenetic reconstruction.

1. domainEukaryota (Chatton, 1925) Whittaker & Margulis, 1978
2. kingdomAnimalia
3. phylumChordata
4. subphylumVertebrata
5. infraphylumGnathostomata
6. parvphylumOsteichthyes
7. megaclassTetrapoda
8. classMammalia Linnaeus, 1758
9. subclassTheria Parker & Haswell, 1897
10. infraclassEutheria Gill, 1872
11. orderRodentia Bowdich, 1821
12. suborderMyomorpha Brandt, 1855
13. superfamilyMuroidea Illiger, 1811
14. familyCricetidae Fischer, 1817
15. subfamilySigmodontinae Wagner, 1843
16. genusCalomys Waterhouse, 1837
17. speciesCalomys expulsus (Lund, 1841)

Close classified relatives

These entries share the source’s genus, Calomys. They are not necessarily the closest relatives established by molecular evidence.

Browse 593 records assigned to Cricetidae.

Documented distribution

Source distribution statements, not a complete range map. A listed locality is not necessarily a place of origin.

Source literature & publication evidence

References attached to this source record, including nomenclatural citations where supplied. This is a selected bibliography; abbreviated citations remain in the source’s form.

1. https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=970663 Source fields: Taxon.tsv dwc:namePublishedIn, Taxon.tsv dcterms:references

Origins, evidence & remaining research

Name authority and publication references document nomenclature where the source supplies it. They do not establish evolutionary origins or the earliest fossil occurrence.

Specimen-level evidence, morphology, ecological research, phylogenetic studies, a comprehensive bibliography and a located literary passage have not yet been compiled for this record.

Dataset citation & attribution

This exact taxon in ChecklistBank · Catalogue of Life 2026-09-11

Catalogue of Life 2026-09-11; dataset 316321; doi:10.48580/dgz5n. https://creativecommons.org/licenses/by/4.0/ . Retrieved 5 October 2026.

Stable key: col:PYL4. Classification follows source parent identifiers. English common names may vary by region.