Last updated: 24th January 2026
Before Dinosaurs: Cambrian Period
Life During the Cambrian Period
Imagine a world with no trees, no animals on land, and no plants covering the ground. Over 500 million years ago, during the Cambrian period, Earth looked completely different from today. Almost all life lived in the oceans, and these seas were bursting with strange and fascinating creatures.
The Cambrian period is famous for a huge burst of evolution known as the Cambrian Explosion. During this time, life became far more complex. Many of the major animal groups we recognise today, such as arthropods (the group that includes insects, spiders and crabs), first appeared in these ancient oceans.
If you could dive into a Cambrian sea, you’d see an alien landscape full of unusual animals:
- Trilobites scuttling along the sea floor.
- Anomalocaris, a top predator with grasping mouthparts.
- Opabinia, a creature with five eyes and a long, flexible proboscis.
Although the Cambrian world might seem strange, it laid the foundations for all complex life that followed, including us.
Exploring this period helps scientists understand how life evolved and why the oceans played such an important role in shaping Earth’s early ecosystems.
Quick links
Cambrian Period Life (541–485 Ma)
Key features:
Rapid diversification of marine life; first animals with hard parts.
- Anomalocaris: Apex predator of the Cambrian seas.
- Opabinia: Five eyed, soft bodied predator.
- Hallucigenia: Spiny lobopodian from the Burgess Shale fauna.
- Trilobites: Extremely diverse arthropods that first appear in early Cambrian rocks.
Anomalocaris
Anomalocaris was one of the largest predators of the Cambrian seas, swimming with undulating lobes and using its grasping appendages to seize prey. Its compound eyes and circular, pineapple‑ring mouth made it a formidable hunter in early marine ecosystems.
Hallucigenia
Hallucigenia was a small, worm-like animal that lived long before dinosaurs, known for its spiny back and soft, tentacle-like legs. It crawled along the seafloor during the Cambrian, feeding on tiny organisms and becoming famous for its strange body.
Opabinia
Opabinia was a strange, soft-bodied animal that lived long before dinosaurs, known for its five eyes and long, flexible snout with a claw-like tip. It swam through Cambrian seas, using its unusual proboscis to grab food from the seafloor.
Trilobite
Trilobite was a hard-shelled arthropod that lived long before dinosaurs, known for its segmented body and compound eyes. It crawled along the seafloor of ancient oceans, feeding on detritus and small prey, and became one of the most diverse and widespread animals of the Paleozoic.
You may also be intrested in:
- Extinct Animals: A-Z
- Dinosaurs: A-Z
Tags: Cambrian Period, Cambrian Explosion, prehistoric oceans, early life on Earth, trilobites, before dinosaurs, Palaeozoic Era.
© 2012 science-resources.co.uk. All rights reserved | Design by W3layouts
Before Dinosaurs: Cambrian Period
Life During the Cambrian Period
Imagine a world with no trees, no animals on land, and no plants covering the ground. Over 500 million years ago, during the Cambrian period, Earth looked completely different from today. Almost all life lived in the oceans, and these seas were bursting with strange and fascinating creatures.
The Cambrian period is famous for a huge burst of evolution known as the Cambrian Explosion. During this time, life became far more complex. Many of the major animal groups we recognise today, such as arthropods (the group that includes insects, spiders and crabs), first appeared in these ancient oceans.
If you could dive into a Cambrian sea, you’d see an alien landscape full of unusual animals:
- Trilobites scuttling along the sea floor.
- Anomalocaris, a top predator with grasping mouthparts.
- Opabinia, a creature with five eyes and a long, flexible proboscis.
Although the Cambrian world might seem strange, it laid the foundations for all complex life that followed, including us.
Exploring this period helps scientists understand how life evolved and why the oceans played such an important role in shaping Earth’s early ecosystems.
Quick links
Cambrian Period Life (541–485 Ma)
Key features:
Rapid diversification of marine life; first animals with hard parts.
- Anomalocaris: Apex predator of the Cambrian seas.
- Opabinia: Five eyed, soft bodied predator.
- Hallucigenia: Spiny lobopodian from the Burgess Shale fauna.
- Trilobites: Extremely diverse arthropods that first appear in early Cambrian rocks.
Anomalocaris
Anomalocaris was one of the largest predators of the Cambrian seas, swimming with undulating lobes and using its grasping appendages to seize prey. Its compound eyes and circular, pineapple‑ring mouth made it a formidable hunter in early marine ecosystems.
Hallucigenia
Hallucigenia was a small, worm-like animal that lived long before dinosaurs, known for its spiny back and soft, tentacle-like legs. It crawled along the seafloor during the Cambrian, feeding on tiny organisms and becoming famous for its strange body.
Opabinia
Opabinia was a strange, soft-bodied animal that lived long before dinosaurs, known for its five eyes and long, flexible snout with a claw-like tip. It swam through Cambrian seas, using its unusual proboscis to grab food from the seafloor.
Trilobite
Trilobite was a hard-shelled arthropod that lived long before dinosaurs, known for its segmented body and compound eyes. It crawled along the seafloor of ancient oceans, feeding on detritus and small prey, and became one of the most diverse and widespread animals of the Paleozoic.
Tags: Cambrian Period, Cambrian Explosion, prehistoric oceans, early life on Earth, trilobites, before dinosaurs, Palaeozoic Era.
© 2012 science-resources.co.uk. All rights reserved | Design by W3layouts