Spriggina
Spriggina is a genus of early bilaterian animals whose relationship to living animals is unclear. Fossils of Spriggina are known from the late Ediacaran period in what is now South Australia. Spriggina floundersi is the official fossil emblem of South Australia; it has been found nowhere else.
| Spriggina Temporal range: Late Ediacaran, | |
|---|---|
| Fossil of S. floundersi. Scale in millimetres | |
| Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | †Proarticulata |
| Class: | †Cephalozoa |
| Family: | †Sprigginidae |
| Genus: | †Spriggina Glaessner, 1958 |
| Species: | †S. floundersi |
| Binomial name | |
| †Spriggina floundersi Glaessner, 1958 | |
The organism reached 3–5 centimetres (1.2–2.0 in) in length and may have been predatory. Its bottom was covered with two rows of tough interlocking plates, while one row covered its top; its front few segments fused to form a "head."
The affinity of Spriggina is unknown; it has been variously classified as an annelid worm, a rangeomorph-like frond, a variant of Charniodiscus, a proarticulatan, an arthropod (perhaps related to the trilobites), or even an extinct phylum. The lack of known segmented legs or limbs, coupled with the presence of glide reflection instead of symmetric segments, suggests that an arthropod classification is unlikely despite some superficial resemblance.
The genus Spriggina originally contained three different species—S. floundersi, S. ovata, and S. borealis—but S. ovata is now considered a junior synonym of Marywadea ovata, while the phylogenetic status of S. borealis remains a subject of debate.