Laurasiatheria: : The Diverse Mammals of the Northern Hemisphere

In a Nutshell: What is Laurasiatheria?

The superorder Laurasiatheria is one of the two major branches of Boreoeutheria, a magnorder of placental mammals. This group includes some of the most ecologically diverse mammals on Earth, such as carnivores, hoofed mammals, bats, whales, and insectivores.

Laurasiatherians originated in Laurasia, the ancient northern supercontinent that included North America, Europe, and Asia. They evolved into a wide range of species, from fast-running predators to ocean giants and even the only flying mammals—bats.

Laurasiatheria includes everything from tiny shrews to massive whales, covering terrestrial, aerial, and aquatic environments.

Keep reading to learn more about Laurasiatheria!

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Key Characteristics of Laurasiatheria

Laurasiatherians share several evolutionary, anatomical, and physiological traits that distinguish them from other placental mammals.

Evolutionary Origins

Northern origins – Evolved in Laurasia, while their sister group, Euarchontoglires, also diversified in the same region.
Survivors of mass extinctions – Laurasiatherians rapidly expanded after the Cretaceous-Paleogene extinction event (66 MYA), leading to today’s wolves, whales, bats, and hoofed mammals.

Anatomical and Physiological Traits

Diverse limb adaptations – Laurasiatherians evolved for running (horses, deer), flying (bats), and swimming (whales, seals).
Varied dentition – From the carnivorous teeth of wolves and tigers to the grinding molars of deer and rhinos.
Enhanced sensory abilities – Many laurasiatherians, including bats (echolocation) and carnivores (keen smell and vision), have highly specialized sensory adaptations.

Reproductive and Developmental Aspects

Extended gestation in large species – Many laurasiatherians (e.g., whales, horses, and big cats) have long pregnancies, producing well-developed young.
Diverse parental care strategies – Some, like whales and felines, provide extended parental care, while others, like deer and horses, have precocial young capable of running shortly after birth.

Major Groups Within Laurasiatheria

Laurasiatheria is divided into several distinct orders, each with unique adaptations.

Carnivora (Carnivores: Wolves, Lions, Bears, and Relatives)

This order includes cats, dogs, bears, otters, and hyenas, among others.

Apex predators – Many are top predators, like lions, wolves, and tigers.
Highly adaptable – Carnivorans inhabit forests, savannas, polar regions, and even aquatic environments (e.g., otters and seals).
Sharp teeth and claws – Specialized for hunting, scavenging, or omnivory.

Perissodactyla (Odd-Toed Ungulates: Horses, Rhinos, Tapirs)

This order includes mammals with an odd number of toes on each foot.

Powerful runners – Horses and zebras evolved long limbs for endurance running.
Massive herbivores – Rhinos are among the largest land mammals, relying on sheer size for defense.
Hindgut fermenters – Digestive systems adapted to breaking down tough plant material.

Artiodactyla (Even-Toed Ungulates: Deer, Pigs, Cows, and Whales)

This diverse order includes hoofed mammals with even-numbered toes, as well as whales and dolphins.

Domesticated species – Includes cattle, sheep, and pigs, essential to human agriculture.
Whales and dolphins – The Cetacea subgroup evolved from land-dwelling ancestors into fully aquatic giants.
Ruminant digestion – Many, like cows and deer, have complex stomachs for digesting plant material.

Chiroptera (Bats: The Only Flying Mammals)

Bats are the only mammals capable of true flight and make up over 20% of all mammal species!

Echolocation – Many bats navigate and hunt using high-frequency sound waves.
Diet diversity – Some eat insects, others feed on fruit, nectar, or even blood (vampire bats).
Global distribution – Found on every continent except Antarctica.

Eulipotyphla (Insectivores: Hedgehogs, Shrews, Moles)

This order consists of small, insect-eating mammals with primitive traits.

Voracious insect hunters – Many consume their body weight in food daily.
Underground lifestyle – Moles are specialized for digging tunnels.
Simple teeth – Unlike other mammals, their teeth are uniform and sharp.

Laurasiatheria vs. Euarchontoglires: Key Differences

Laurasiatheria and Euarchontoglires are the two superorders of Boreoeutheria. While Laurasiatherians are known for large predators, hoofed mammals, bats, and ocean giants, Euarchontoglires includes primates, rodents, and rabbits.

Feature	Laurasiatheria (Diverse Northern Mammals)	Euarchontoglires (Primates, Rodents, Rabbits)
Origin	Laurasia (North America, Europe, Asia)	Laurasia (same region)
Major Groups	Carnivores, bats, whales, hoofed mammals, insectivores	Primates, rodents, rabbits, colugos
Dietary Adaptations	Carnivory, herbivory, omnivory, insectivory	Herbivory, omnivory, specialized diets (fruit, seeds)
Notable Features	Apex predators, aquatic mammals, flying mammals	Large-brained primates, fast-reproducing rodents

Key takeaway: Laurasiatherians dominate predator-prey ecosystems, open plains, and oceans, while Euarchontoglires thrive in forests, grasslands, and underground burrows.

Summary

Laurasiatheria includes some of the most diverse mammal groups, from lions and whales to bats and horses.
It consists of five major orders: Carnivora, Perissodactyla, Artiodactyla (including whales), Chiroptera, and Eulipotyphla.
Laurasiatherians evolved in Laurasia, the ancient supercontinent including present-day North America, Europe, and Asia, spreading to nearly every ecosystem on Earth.
This superorder contains mammals adapted to land, sea, and air, making it one of the most ecologically successful mammal groups.
Laurasiatherians include Earth’s top predators, largest land herbivores, only flying mammals, and fully aquatic placental mammals.