Tamga hamulifera is a disk-shaped fossil from Precambrian

Precambrian

The Precambrian is the name which describes the large span of time in Earth's history before the current Phanerozoic Eon, and is a Supereon divided into several eons of the geologic time scale...

 strata of the White Sea

White Sea

The White Sea is a southern inlet of the Barents Sea located on the northwest coast of Russia. It is surrounded by Karelia to the west, the Kola Peninsula to the north, and the Kanin Peninsula to the northeast. The whole of the White Sea is under Russian sovereignty and considered to be part of...

 area, in Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

.

Description

The small (3-5 mm in long), disk-shaped fossil has seven hook-like isomers in a star-like arrangement in the clearly expressed peripheral undivided zone. T. hamulifera is probably a member of Proarticulata

Proarticulata

Proarticulata is a proposed extinct phylum of very early bilateral animals known from fossils found in the Ediacaran fauna. Mikhail A. Fedonkin describes animals in Proarticulata as having a "shield-like" shape, an unmineralized, thin, flexible carapace and a thick, segmented body...

, as it is strongly similar to Praecambridium sigillum

Praecambridium sigillum

Praecambridium sigillum resembles a segmented trilobite-like arthropod, though many experts place it within the proarticulatan family Dickinsoniidae. It is from either the Late Precambrian or Lower Cambrian of Ediacara Hills, Australia, about 590 to 530 million years ago. This beast is known from...

 in the general shape, and the presence of hooklike isomers; Tamga is also similar to Onega stepanovi in the flattened body with a compact group of ledges-isomers in the central part encircled by an undivided zone.
The fossils of Tamga could possibly be sclerites, for example, as sclerites of palaeoscolecid

Palaeoscolecid

The palaeoscolecids are a group of ecdysozoan worms resembling armoured priapulids. They are known from the Lower Cambrian to the late Silurian; they are mainly found as disarticulated sclerites, but are also preserved in many of the Cambrian lagerstatten...

s show a similar shape, a disk with a ring or rows of tubercles in the center. But the size of Tagmas fossils is two orders of magnitude less than those of palaeoscolecid sclerites, and no mineralized sclerites of any sort have ever been found or diagnosed in the Vendian–Ediacaran

Ediacaran

The Ediacaran Period , named after the Ediacara Hills of South Australia, is the last geological period of the Neoproterozoic Era and of the Proterozoic Eon, immediately preceding the Cambrian Period, the first period of the Paleozoic Era and of the Phanerozoic Eon...

 communities.

Etymology

The generic name is taken from the Turkish word, "tamga", meaning seal

Seal (device)

A seal can be a figure impressed in wax, clay, or some other medium, or embossed on paper, with the purpose of authenticating a document ; but the term can also mean the device for making such impressions, being essentially a mould with the mirror image of the design carved in sunken- relief or...

 or cattle brand. The specific name is a crasis

Crasis

Crasis is a type of contraction in which two vowels or diphthongs merge into one new vowel or diphthong — making one word out of two. Crasis occurs in Portuguese and Arabic as well as in Ancient Greek, where it was first described.-French:...

 compound word, taken from Latin, of hamulus (small hook), and the feminine form of feros, "to bear." Thus, the scientific name can be translated as a "seal that bears small hooks."