How much do we know about species on Earth?

species on Earth

 

Quick fact: only 14 percent of all species have been discovered on Earth. (source: wikipedia.org)

What is the definition of species:

According to Wikipedia: A species is often defined as the largest group of organisms where two individuals are capable of reproducing fertile offspring (hybrids), typically using sexual reproduction. While in many cases this definition is adequate, the difficulty of defining species is known as the species problem.

What is the number of species Identified on Earth?

Scientists have described well over over 1.7 million of the world's species of animals, plants, insects and algae. (currentresults.com)

How many species known to currently exist in the world?

 
Category Species Totals
Vertebrate Animals    
Mammals 5,513  
Birds 10,425  
Reptiles 10,038  
Amphibians 7,302  
Fishes 32,900  
Total Vertebrates   66,178
Invertebrate Animals    
Insects 1,000,000  
Spiders and scorpions 102,248  
Molluscs 85,000  
Crustaceans 47,000  
Corals 2,175  
Others 68,827  
Total Invertebrates   1,305,250
Plants    
Flowering plants (angiosperms) 268,000  
Conifers (gymnosperms) 1,052  
Ferns and horsetails 12,000  
Mosses 16,236  
Red and green algae 10,386  
Total Plants   307,674
Others    
Lichens 17,000  
Mushrooms 31,496  
Brown algae 3,127  
Total Others   51,623
TOTAL SPECIES   1,730,725

Note: The species totals do not include domestic animals and single-celled organisms

(Source: currentresults.com) 

Ref: Redlist

Top 5 oldest species on Earth:

1. SPONGE - 760 MILLION YEARS OLD

The oldest evidence of a sea sponge found was a fossil discovered just last year in a 760-million-year-old rock. 

(Source: National Geographic)

2. JELLYFISH - 505 MILLION YEARS OLD

In 2007, researchers from the University of Kansas found new fossil evidence of jellyfish going back over half a billion years, 200 million more than the oldest know jellyfish fossils up until that point. So it's more accurate to say that jellyfish are 505 million years old at least.

(Source: Science Daily)

3. NAUTILUS - 500 MILLION YEARS OLD

They survived all the major mass extinctions that hit the reset button on life throughout the globe since half a billion years ago.

(Source: phys.org)

4. HORSESHOE CRAB - 445 MILLION YEARS OLD

The creatures were already considered one of the oldest living animals on the planet, the new fossil proved that they were a full 100 million years older than we previously knew

(Source: Science Daily)

5. COELACANTH - 360 MILLION YEARS OLD

When scientists studied about a fish species which were so similar to the ancient fish that eventually evolved to crawl out of the water and become the first land vertebrate, they found about coelacanth.

(Source: Los Angeles Times)

Some video about new and weird species:

 What about you? How much do you know about species on Earth?