Bryan McAllister’s personal reference notebook
July 30, 2026Short & citedBlog
Civic Viewpoint.
A quiet encyclopedia with a personal desk
Kept by Bryan McAllister — short guides, clear facts, and the Canadian angle when it matters.
Field Notes • Paleontology

Megalodon

Megalodon is an extinct giant shark best known from its fossil teeth and vertebrae.

Updated July 30, 20261 min readCited sources

Megalodon is an extinct giant shark known mainly from fossil teeth and vertebrae. It lived from about 23 to 3.6 million years ago and is considered the largest shark ever.

What it is

Megalodon (Otodus megalodon) was a massive predatory shark from the Miocene and Pliocene epochs. Its name means 'big tooth,' and most of what we know comes from its fossilized teeth and vertebrae, as soft tissue does not preserve.

Key details

Common size estimates place megalodon at 10.5 to 18 metres long, though some studies suggest larger individuals. Its teeth can exceed 180 millimetres in slant height. The species went extinct around 2.6 to 3.6 million years ago, likely due to climate shifts and changes in prey.

Why it matters

Megalodon is a key subject in paleontology, helping scientists understand ancient marine ecosystems. For Canadian readers, it appears in museum exhibits and fossil education, sparking interest in prehistoric life and ocean history.

In short

  • Megalodon is an extinct giant shark, Otodus megalodon.
  • It lived 23 to 3.6 million years ago.
  • Size estimates range from 10.5 to 18 metres.
  • Extinction is placed around 2.6 to 3.6 million years ago.
Canadian angle

Megalodon is relevant to Canadian readers through museum displays, fossil education, and broader interest in paleontology and ancient marine life.

Quick questions

What is a megalodon?
Megalodon is an extinct giant shark, scientifically known as Otodus megalodon, that lived millions of years ago and is known mainly from fossils.
How big was a megalodon?
Common estimates place megalodon around 10.5 to 18 metres long, though some studies have proposed larger individuals above 20 metres.
Could megalodon still exist?
No verified evidence shows that megalodon survives today. It is regarded as extinct, and its fossil record ends millions of years ago.

Sources

  1. Wikipedia — https://en.wikipedia.org/wiki/Megalodon
    Supports: Time range, size estimates, tooth size, and extinct shark description.
  2. Encyclopaedia Britannica — https://www.britannica.com/animal/megalodon
    Supports: Megalodon as an extinct megatooth shark and one of the largest sharks/fish known.
  3. National Geographic España — https://www.nationalgeographic.com.es/ciencia/se-descubre-verdadero-tamano-megalodon-es-mas-grande-que-creiamos_24424
    Supports: Extinction estimate, tooth size, and larger size estimates.
  4. BBC Mundo — https://www.bbc.com/mundo/articles/c4nr4z7r7lyo
    Supports: Duration of dominance, extinction timing, and tooth size example.
  5. Wikipedia — https://fr.wikipedia.org/wiki/M%C3%A9galodon
    Supports: French-language description, time range, and meaning of the name.