ZME Science
No Result
View All Result
ZME Science
No Result
View All Result
ZME Science

Home → Science

Mammals’ evolutionary success relied on our ancestors growing very tiny

Sometimes it pays to be the smallest fish in the pond.

Alexandru MicubyAlexandru Micu
September 17, 2018 - Updated on July 24, 2019
in Biology, News, Research, Science, Studies
A A
Share on FacebookShare on TwitterSubmit to Reddit

Mammals cashed in big on growing smaller, new research reveals.

Mammaliaform Morgauncodon
Morganucodon, a mamaliaformes and one of the best-preserved species from which all mammals originate, grew up to only 4-6 cm length.
Image credits Bob Nicholls.

The bubbly evolution of mammal species over the last 200 million years is owed in no small part to their propensity for growing smaller, a new paper reports. This trend is most evident when compared to that of the dinosaurs — the former de-facto winners of the evolutionary lottery — which spawned some of the largest beasts to ever walk the Earth.

Smaller, better, harder, stronger

When mammals first started popping up around 200 million years ago, our planet was still dominated by dinosaurs. So for the following 150-ish million years, mammals literally and figuratively kept a low profile. While dinosaurs were growing bigger, mammals shrank in size.

An international team of researchers set out to understand why and how this shift took place. Using modern computer modeling and analysis, they analyzed the skeletons of our tiny ancestors to better document their evolutionary path.

Mammals stand out among all other vertebrates on the planet in that they have a single bone bearing teeth for their lower jaw. Everyone else has more complex lower jaws, formed from no fewer than five bones linked together, the team explains.

As mammals evolved, most of these bones shrank in size and became more simplified. The new jaw retained a single bone, and the others moved higher in the skull, into the inner ear. They now help us hear.

The team focused their research efforts on understanding how this lower jaw restructuring process took place — as they were occurring, these changes had to allow the animal to keep feeding itself and hear, else they wouldn’t be viable organisms. Starting from X-ray computed tomography (CT) scans of several fossil skulls and lower jaws, the team created digital models of the bones. Later, they ran these models through extensive computer simulations to see how they would function.

RelatedPosts

What causes cavities and how to spot tooth decay
World’s oldest fillings come from the stone age and they’re basically asphalt
Mammals eating dinosaurs: flipping the script on the Cretaceous food chain
Going out on a limb: regrowing human limbs is possible, although we can’t yet do it

For smaller animals, the team reports, jaw bones experience reduced stress when feeding. The jaws themselves could thus become simpler and tinier while still retaining enough structural strength to bite through prey.

“Our results provide a new explanation of how the mammalian jaw evolved over 200 million years ago,” says Dr Stephan Lautenschlager, lead author of the paper and lecturer at the University of Birmingham.

“Getting very small appears to have been crucial for our mammalian ancestors. This allowed them to reduce the stresses in the jaw during feeding and made the restructuring of the jaw bones possible.”

University of Bristol Professor Emily Rayfield, who co-authored the study, says that the research addresses a 50-year-old open debate in paleontology.

“Using computational methods we can offer explanations to how our mammalian ancestors were able to maintain a working jaw while co-opting bones into a complex sound detection system,” she explains. “Our research is about testing ideas of what makes mammals unique among the animal kingdom, and how this may have come about.”

The paper “The role of miniaturisation in the evolution of the mammalian jaw and middle ear” has been published in the journal Nature.

Tags: bonesjawMammaliaformmammalsteeth

ShareTweetShare
Alexandru Micu

Alexandru Micu

Stunningly charming pun connoisseur, I have been fascinated by the world around me since I first laid eyes on it. Always curious, I'm just having a little fun with some very serious science.

Related Posts

Health

Bioengineered tooth “grows” in the gum and fuses with existing nerves to mimic the real thing

byMihai Andrei
6 days ago
Biology

The First Teeth Grew on the Skin of 460-Million-Year-Old Fish and Were Never Meant for Chewing

byTibi Puiu
3 weeks ago
Animals

Same-Sex Behavior Is Surprisingly Common in Animals — Humans Are No Exception

byMihai Andrei
2 months ago
Health

Human-like Teeth Grown in Pigs Could Make Dental Implants a Thing of the Past

byTibi Puiu
4 months ago

Recent news

Scientists Discover a Way to Store Data in Ice Using Only Air Bubbles

June 19, 2025

Elon Musk says he wants to “fix” Grok after the AI disagrees with him

June 19, 2025
a denisovan skull

The Face of a Ghost: 146,000-Year-Old Skull Finally Reveals What Denisovans Looked Like

June 19, 2025
  • About
  • Advertise
  • Editorial Policy
  • Privacy Policy and Terms of Use
  • How we review products
  • Contact

© 2007-2025 ZME Science - Not exactly rocket science. All Rights Reserved.

No Result
View All Result
  • Science News
  • Environment
  • Health
  • Space
  • Future
  • Features
    • Natural Sciences
    • Physics
      • Matter and Energy
      • Quantum Mechanics
      • Thermodynamics
    • Chemistry
      • Periodic Table
      • Applied Chemistry
      • Materials
      • Physical Chemistry
    • Biology
      • Anatomy
      • Biochemistry
      • Ecology
      • Genetics
      • Microbiology
      • Plants and Fungi
    • Geology and Paleontology
      • Planet Earth
      • Earth Dynamics
      • Rocks and Minerals
      • Volcanoes
      • Dinosaurs
      • Fossils
    • Animals
      • Mammals
      • Birds
      • Fish
      • Amphibians
      • Reptiles
      • Invertebrates
      • Pets
      • Conservation
      • Animal facts
    • Climate and Weather
      • Climate change
      • Weather and atmosphere
    • Health
      • Drugs
      • Diseases and Conditions
      • Human Body
      • Mind and Brain
      • Food and Nutrition
      • Wellness
    • History and Humanities
      • Anthropology
      • Archaeology
      • History
      • Economics
      • People
      • Sociology
    • Space & Astronomy
      • The Solar System
      • Sun
      • The Moon
      • Planets
      • Asteroids, meteors & comets
      • Astronomy
      • Astrophysics
      • Cosmology
      • Exoplanets & Alien Life
      • Spaceflight and Exploration
    • Technology
      • Computer Science & IT
      • Engineering
      • Inventions
      • Sustainability
      • Renewable Energy
      • Green Living
    • Culture
    • Resources
  • Videos
  • Reviews
  • About Us
    • About
    • The Team
    • Advertise
    • Contribute
    • Editorial policy
    • Privacy Policy
    • Contact

© 2007-2025 ZME Science - Not exactly rocket science. All Rights Reserved.