Animal style art is characterized by its emphasis on animal and bird motifs, and the term describes an approach to decoration which existed from China to Northern Europe in the early Iron Age, and the barbarian art of the Migration Period. It is a zoomorphic style of decoration, and the Animal Style was used to decorate small objects by warrior-herdsmen, whose economy was based entirely on animals and plunder.
Perm animal style 
A distinct style of decoration found in objects made of various copper alloys near the Ural mountains and the Volga and Kama rivers in today's Russia beginning from about 7th - 5th centuries BCE. 
Germanic animal style 
The study of Germanic zoomorphic decoration was pioneered by Bernhard Salin in a work published in 1904. He classified animal art of the period roughly from 400 to 900 into three phases: Styles I, II and III. The origins of these different phases are still the subject of considerable debate; the development of trends in late-Roman popular art in the provinces is one element, and the older traditions of nomadic Asiatic steppe peoples another. The first two styles are found very widely across Europe in the art of the "barbarian" peoples of the Migration Period.
Style I. First appears in northwest Europe, it became a noticeable new style with the introduction of the chip carving technique applied to bronze and silver in the 5th century. It is characterized by animals whose bodies are divided into sections, and typically appear at the fringes of designs whose main emphasis is on abstract patterns.
Style II. After about 560-570 Style I was in decline and Salin's Style II began to replace it. Style II's animals are whole beasts, but their bodies are elongated into "ribbons" which intertwined into symmetrical shapes with no pretence of naturalism, and rarely any legs, so that they tend to be described as serpents, although the heads often have characteristics of other types of animal. The animal becomes subsumed into ornamental patterns, typically using interlace. Thus two bears are facing each other in perfect symmetry ("confronted"), forming the shape of a heart. Examples of Style II can be found on the gold purse lid (picture) from Sutton Hoo (ca. 625).
After about 700 localised styles develop, and it is no longer very useful to talk of a general Germanic style.  Salin Style III is found mainly in Scandinavia, and may also be called Viking art. Interlace, where it occurs, becomes less regular and more complex, and if not three-dimensional animals are usually seen in profile but twisted, exaggerated, surreal, with fragmented body parts filling every available space, creating an intense detailed energetic feel. Animals' bodies become hard for the unpractised viewer to read, and there is a very common motif of the "gripping beast" where an animal's mouth grips onto another element of the composition to connect two parts. Animal style was one component, along with Celtic art and late classical elements, in the formation of style of Insular art and Anglo-Saxon art in the British Isles, and through these routes and others on the Continent, left a considerable legacy in later Medieval art.
See also 
- Migration Period art
- Scythian art
- Thracian art
- Persian-Sassanid art patterns
- Carolingian art
- Emma C.Bunker, Animal Style Art from East to West, Asia Society. p. 13
- Biography on swedish Wikipedia
- Die altgermanische Thierornamentik, Stockholm 1904, The Open Library online text, written in German and heavily illustrated.
- Rituals of power: from late antiquity to the early Middle Ages, By Frans Theuws, Janet L. Nelson, p. 45