Volumetric reconstruction of a tooth whorl viewed from its lingual side (holotype of Qianodus duplicis). The specimen is just over 2 mm in length.

source:Zhu, et al

Rare Chinese fossil teeth have changed scientists’ beliefs about the evolution of vertebrates.

source:Zhu, et al

A virtual section along the length of a tooth whorl in side view (holotype of Qianodus duplicis). The specimen is just over 2 mm in length.

source:Zhu, et al

including solitary teeth identified as belonging to a new species (Qianodus duplicis) of primitive jawed vertebrate from the ancient Silurian period (about 445 to 420 million years ago).

source:Zhu, et al

The discovery indicates that the well-known jawed vertebrate groups from the so-called “Age of Fishes” (420 to 460 million years ago)

source:Zhu, et al

A reconstruction of Qianodus duplicis, a primitive jawed vertebrate.

source:Zhu, et al

“Despite their peculiarities, tooth whorls have, in fact, been reported in many extinct chondrichthyans and osteichthyan lineages

source:Zhu, et al

“Some of the early chondrichthyans even built their dentition entirely from closely spaced whorls.”

source:Zhu, et al