Typhloesus [UPSC Notes]

Typhloesus has been an evolutionary enigma in scientific circles for many decades. It has confused scientists as to where it belonged in the tree of life. This forms an important topic for the IAS Exam science and technology section.

Typhloesus

Typhloesus wellsi lived about 330 million years ago (Carboniferous period) and was discovered in the Bear Gulch Limestone fossil site in Montana (USA) in the late 1960s, with the remains of other species.

Typhloesus Features

• A soft rugby ball-shaped body approximately 90 mm (9 cm) in length.
• A prominent fin at the posterior end to propel it forward.
• Neither a backbone nor anus.
• Lacking a shell.

Typhloesus Feeding Apparatus

• Researchers studied Typhloesus wellsi specimens acquired by the Royal Ontario Museum and found evidence of a feeding apparatus similar to the toothed ribbon – radula (as seen in molluscs). 
• The feeding apparatus is located in the foregut of Typhloesus and is a 4 mm long structure consisting of two rows of about 20 triangular teeth, curved backwards.
• This suggests that Typhloesus likely turned the structure inside out, projecting it beyond the body to capture prey.

Image Source – Jean Bernard Caron, Royal Ontario Museum.

Typhloesus wellsi Latest News

Researchers have proposed that T.wellsi was an early gastropod, which is a group of molluscs that includes modern snails and slugs because many of these living creatures extend their foregut to capture prey. 

• However, the presence of radula does not definitely declare the species to be a mollusc because animal lineage can evolve radula-like features independently from one another.
• Mark Purnell, a professor of Paleobiology at the University of Leicester in England has opined that although the new information unearthed by researchers is interesting, it does not necessarily point out to what exactly this species was.

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