Eozostrodon
Encyclopedia
Eozostrodon was one of the earliest mammal
s. It lived during the late Triassic
and the early Jurassic
, about 210 million years ago. Eozostrodon was one of the largest early mammals, measuring more than a meter long.
As with most early mammals, the classification of Eozostrodon is uncertain.
Like modern monotreme
s, this mammal laid eggs
. Young were then fed with milk from their mother's mammary gland
s. Its teeth were typically mammalian, being differentiated into molar
s and premolar
s with triangular cusps.
With its long snout, four legs, eight toes, clawed paws and a long hairy tail, Eozostrodon resembled a shrew
.
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s. It lived during the late Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
and the early Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
, about 210 million years ago. Eozostrodon was one of the largest early mammals, measuring more than a meter long.
As with most early mammals, the classification of Eozostrodon is uncertain.
Like modern monotreme
Monotreme
Monotremes are mammals that lay eggs instead of giving birth to live young like marsupials and placental mammals...
s, this mammal laid eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
. Young were then fed with milk from their mother's mammary gland
Mammary gland
A mammary gland is an organ in mammals that produces milk to feed young offspring. Mammals get their name from the word "mammary". In ruminants such as cows, goats, and deer, the mammary glands are contained in their udders...
s. Its teeth were typically mammalian, being differentiated into molar
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
s and premolar
Premolar
The premolar teeth or bicuspids are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant, making eight premolars total in the mouth. They have at least two cusps. Premolars can be considered as a 'transitional tooth' during chewing, or...
s with triangular cusps.
With its long snout, four legs, eight toes, clawed paws and a long hairy tail, Eozostrodon resembled a shrew
Shrew
A shrew or shrew mouse is a small molelike mammal classified in the order Soricomorpha. True shrews are also not to be confused with West Indies shrews, treeshrews, otter shrews, or elephant shrews, which belong to different families or orders.Although its external appearance is generally that of...
.