Three truths
- Timed
- Began about 520 million years ago · the last 12% of life's story
- Named
- ≈70,000 named living species · 4.1% of all named
- Weighed
- At least ≈0.87 Gt C · 0.2% or more of all life's carbon
- Part of All other animals (total minus the parts above) (≈0.13 Gt C), not measured separately.
Eukaryotes · animals · group
Vertebrates
Vertebrata
Living · roughly 70,000 described species
Animals with a backbone or its precursor, including fish, amphibians, reptiles, birds and mammals.
Key characteristics
- Backbone of vertebrae or cartilage
- A skull protecting the brain
- Internal skeleton that grows with the body
- Branched off
- About 560 million years ago (approximate)
- Parent lineage
- Chordates
Child lineages
Classification
Sources
- Vertebrate (Wikipedia) · Wikipedia
- TimeTree: the timescale of life · TimeTree
- Open Tree of Life · Open Tree of Life
- Tree of Life Web Project · Tree of Life Web Project