[knowledgepower21 (OP)]

Scientists tell us the best way to protect endangered species is to protect the places where they live. Get involved by volunteering at your local nature center or wildlife refuge. Go wildlife or bird watching in nearby parks. Wildlife related recreation creates millions of jobs and supports local businesses.

Here are some citically endangered species- taken from the website worldwildlife.org
COMMON NAME   SCIENTIFIC NAME   CONSERVATION STATUS ↓
Amur Leopard   Panthera pardus orientalis   Critically Endangered
Black Rhino   Diceros bicornis   Critically Endangered
Bornean Orangutan   Pongo pygmaeus   Critically Endangered
Cross River Gorilla   Gorilla gorilla diehli   Critically Endangered
Eastern Lowland Gorilla   Gorilla beringei graueri   Critically Endangered
Hawksbill Turtle   Eretmochelys imbricata   Critically Endangered
Javan Rhino   Rhinoceros sondaicus   Critically Endangered
Orangutan   Pongo abelii, Pongo pygmaeus   Critically Endangered
Saola   Pseudoryx nghetinhensis   Critically Endangered
Sumatran Elephant   Elephas maximus sumatranus   Critically Endangered
Sumatran Orangutan   Pongo abelii   Critically Endangered
Sumatran Rhino   Dicerorhinus sumatrensis   Critically Endangered
Sunda Tiger   Panthera tigris sondaica   Critically Endangered
Vaquita   Phocoena sinus   Critically Endangered
Western Lowland Gorilla   Gorilla gorilla gorilla   Critically Endangered
Yangtze Finless Porpoise   Neophocaena asiaeorientalis ssp. asiaeorientalis   Critically Endangered

[charles1948]

I regret the extinction of Trilobites and Pterodactyls. 

But Life moves on.  That's its beauty. As old species become extinct, fascinating new species evolve.

Otherwise, we wouldn't even be here to discuss it.