Microtherulum

Microtherulum is an extinct genus of eutherian mammal known from the Early Cretaceous Jiufotang Formation of China. It is one of the earliest and most primitive eutherians.

Microtherulum Temporal range: Early Cretaceous (Aptian) 120–118 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Clade:	Eutheria
Genus:	†Microtherulum Wang & Wang, 2023
Type species
Microtherulum oneirodes Wang & Wang, 2023

Description

The genus is known from a mostly complete skeleton, including a well preserved skull, which is about 2 centimetres (0.79 in) long. The ear, which is among the best known in basal eutherians, is microtype, adapted for hearing high-frequency sounds. The dental formula is 5 incisors, 1 canine, 5 premolars and 3 molars in the each half of the upper jaw, and 4 incisors, 1 canine, 5 premolars and 3 molars in each half of the lower jaw, which is typical for basal eutherians.^[1]

Phylogeny

Microtherulum has been placed close to the base of Eutheria.^[1]

	Metatheria
Eutheria	Sinodelphys Ambolestes Acristatherium Microtherulum Cokotherium Juramaia Eomaia Prokennalestes Murtoilestes Montanalestes Daulestes Ukhaatherium Asioryctes Kennalestes Gypsonictops Cimolestes Zalambdalestes Aspanlestes Protungulatum Eoungulatum Leptictis Placentalia