Dickinsonia

Dickinsonia costata

Period

Proterozoic

Location

Australia, Russia, Ukraine

Length

1.4 meters

Weight

Very light (flat body)

Diet

Absorber (absorbed nutrients)

Category

Marine Creatures - Invertebrates

Family

Dickinsoniidae

About Dickinsonia

Dickinsonia costata

Overview

Dickinsonia is one of the most mysterious and ancient creatures ever found! Living during the Ediacaran period about 558-555 million years ago, it was one of Earth's earliest complex life forms. This bizarre oval-shaped organism lived before the famous Cambrian Explosion and looks like nothing alive today—like a quilted pancake or ribbed mat!

Taxonomy & Classification

  • Kingdom: Animalia (probably!)
  • Phylum: Unknown (debated)
  • Period: Ediacaran (Late Precambrian)
  • Diet: Absorber (external digestion)

Scientists debated for decades whether Dickinsonia was an animal, fungus, or something else entirely!

Physical Characteristics

Strange Body Plan

  • Length: Up to 1.4 meters (4.6 feet)
  • Shape: Oval, flat, quilted appearance
  • Segments: Rib-like segments radiating from center
  • Thickness: Only a few millimeters thick!

Unique Features

  • No mouth, gut, or anus
  • No eyes or sensory organs
  • Bilaterally symmetrical (like us!)
  • Had a central groove or ridge
  • Segments didn't match up across the midline

How Did It Live?

Feeding Mystery

Without a mouth or digestive system, how did Dickinsonia eat?

  • Absorbed nutrients directly through its body
  • May have digested microbial mats externally
  • Sat on the seafloor and "ate" what was beneath it
  • Left feeding traces in the sediment
  • Like a living digestive blanket!

Lifestyle

  • Lived on the shallow seafloor
  • Could move slowly across microbial mats
  • Left trace fossils showing movement
  • Probably lived in colonies

The Great Debate

What Was Dickinsonia?

Scientists argued for years:

  • Animal? (most now agree yes!)
  • Giant protozoan?
  • Fungus?
  • Lichen?
  • Extinct kingdom of life?

Proof It's an Animal

In 2018, scientists found cholesterol in Dickinsonia fossils:

  • Cholesterol is an animal molecule
  • Proved Dickinsonia was an animal
  • One of the oldest animals ever found!

The Ediacaran World

Before the Cambrian

Dickinsonia lived in a very different world:

  • No predators (probably)
  • Microbial mats covered the seafloor
  • Soft-bodied creatures dominated
  • The "Garden of Ediacara"
  • Most Ediacaran life went extinct

Fossil Preservation

How Fossils Formed

Dickinsonia fossils are remarkably well-preserved:

  • Buried quickly by sediment
  • Microbial mats helped preservation
  • Found as impressions in sandstone
  • Some preserve fine details

Key Fossil Sites

  • Ediacara Hills, Australia (named after it!)
  • White Sea, Russia
  • Ukraine
  • South Australia

Discovery History

Finding Ancient Life

  • First described in 1947 by Reg Sprigg
  • Named after Ben Dickinson (mining geologist)
  • Found in Ediacara Hills, South Australia
  • One of the first Ediacaran fossils recognized
  • Sparked study of Precambrian life

Why Dickinsonia Matters

Scientific Importance

Dickinsonia teaches us about:

  • The origin of animals
  • Life before the Cambrian Explosion
  • How complex life evolved
  • Ancient ecosystems
  • Earth's earliest animal communities

Cool Facts

  • Dickinsonia is over 550 million years old—older than dinosaurs by 300+ million years!
  • It's one of the oldest animals we've ever found
  • Had no mouth, eyes, or brain!
  • Could grow up to 1.4 meters (4.6 feet) long
  • Scientists found actual animal fat in the fossils
  • It moved like a living bathmat
  • The Ediacaran period is named after where it was found
  • Dickinsonia went extinct before the Cambrian Explosion

Dickinsonia represents one of evolution's earliest experiments with complex animal life—a bizarre, flat creature that thrived in a world we can barely imagine, over half a billion years ago!