Researchers mapped the mammoth family tree by extracting DNA from fossils. Also, scientists found some sessile animals living under Antarctica's ice shelf, and they're really cool.

To get started with Deuterostomia, we will look at phylum Hemichordata. These organisms are known as acorn worms, and they share some but not all of the chordate characteristics. There are fewer than 200 species in this phylum, so let's...

Moving along through Lophophorata, we arrive at Entoprocta, or the goblet worms. There are only about 150 species of these and almost all of them are marine worms. What are they all about? Let's find out now!

It describes the different types of inflorescence seen in different plant species, including the different types of racemose and cymose inflorescence.

Rotifers exist in a wide range of shapes, from globular, sac-like floaters to elongated worm-like swimmers and creepers to sessile types. In this video we'll focus on the four major clades of this phylum - though there is debate around...

Biological Classification Set: This clip introduces the phylum Porifera and the phylum Cnidaria.

T/L cirrus clouds and vapour trails pass over lichen-covered tombstone, UK

T/L track across lichen covered tombstones, St. Genny's churchyard, Cornwall, UK,

Vorticella filter feeding, large nucleus visible

Feathered underwater worm

Purple Anemone (order Actiniaria) and clown fish (Amphiprion sp.), Maldives

Purple Anemone (order Actiniaria) and clown fish (Amphiprion sp.), Maldives

epiphyte in the everglades

Purple Anemone (order Actiniaria) and clown fish (Amphiprion sp.), Maldives

Vorticella feeding

T/L Pilobolus dung fungi spore capsule drying out on grass blade, UK

Whip Coral, Palau, South Pacific

Feather star anchored to coral, Southern Visayas, Philippines

Periclemines shrimp (Periclimenes sp.) feeding above anemone (order Actiniaria), Kungkungan Bay Resort, Sulawesi, Indonesia

Algae in mineral rich river, Rio Tinto, Huelva, Andalusia, Spain

Algae in mineral-rich water, Rio Tinto, Huelva, Andalusia, Spain

Algae in mineral rich water, Rio Tinto, Huelva, Andalusia, Spain

Filograna implexa, a colonial species of Serpulid worm that builds irregular masses of calcareous tubes. Huge shoals of fish swim over the colony. Filmed in Sulawesi, Indonesia

Everglades National Park