Paleontologists from the Nanjing Institute of Geology and Palaeontology on the Chinese language Academy of Sciences and elsewhere have discovered a partial physique fossil of an historic tapeworm preserved in mid-Cretaceous Kachin amber from Myanmar.

The 99-million-year-old amber piece containing the fossil tapeworm (lengthy tentacle) and different inclusions: (A-B) the general view of the amber piece; (C) gleicheniacean trichomes; (D) scale insect nymph; (E) sand grains. Scale bars – 2 mm in (A,B), 0.1 mm in (C-E). Picture credit score: Luo et al., doi: 10.1130/G52071.1.

Parasites are ubiquitous in extant ecosystems however not often preserved within the geological file, particularly parasitic worms.

One such group is Cestoda (tapeworms), a specialised endoparasitic group of flatworms.

These creatures have a posh lifecycle with at the least two hosts, infecting all main teams of vertebrates.

Nevertheless, their fossil file is extraordinarily sparse resulting from their smooth tissue and hid habitats, with the one broadly accepted instance earlier than the Quaternary being eggs found in a shark coprolite from the Permian interval.

The shortage of physique fossils vastly hampers our understanding of their early evolution.

“The fossil file of tapeworms is extraordinarily sparse resulting from their smooth tissues and endoparasitic habitats, which vastly hampers our understanding of their early evolution,” stated Dr. Bo Wang, a researcher with the Nanjing Institute of Geology and Palaeontology on the Chinese language Academy of Sciences.

The brand new fossil shows distinctive exterior (armature sample) and inside (partially invaginated tentacle and rootless hooks) options which can be most in keeping with the tentacles of extant trypanorhynch tapeworms that parasitize marine elasmobranchs (primarily sharks and rays).

“The discover is probably the most convincing physique fossil of a platyhelminth ever discovered,” stated Cihang Luo, a Ph.D. candidate with the Nanjing Institute of Geology and Palaeontology on the Chinese language Academy of Sciences.

“Our research, which gives an distinctive instance of a marine endoparasite trapped in amber, has additionally shed new mild on the taphonomy of amber.”

“Particularly, we confirmed that amber can protect the inner construction of helminths.”

“Utilizing high-resolution micro-CT, we found that the inside of the present fossil has a folded longitudinal construction that seems to run in a spiral across the longitudinal axis and extends to the anteriormost half. That is in keeping with the invaginated tentacle of a trypanorhynch.”

“In the meantime, the rootless hooks are additionally the identical as these of trypanorhynchs.”

“Earlier research had proven that inside constructions could possibly be preserved intact as in extant varieties, however such research all targeted on arthropods.”

A hypothetical ecological reconstruction of the fossil trypanorhynch tapeworm. Picture credit score: Dinghua Yang / Luo et al., doi: 10.1130/G52071.1.

“Our outcomes present that amber can protect the inner construction of helminths corresponding to tapeworms on geologic time scales,” Dr. Wang stated.

“Together with the outstanding instance of a marine endoparasite trapped in amber, some gleicheniacean trichomes and a scale insect nymph had been additionally preserved with the partial worm fossil in the identical amber specimen.”

“This clearly signifies a terrestrial or onshore atmosphere on the time of entrapment in resin.”

“As well as, many sand grains had been evenly distributed all through the amber, suggesting that the fossil was entombed in a sandy atmosphere.”

“Moreover, earlier proof exhibits that the Kachin amber was deposited in a near-shore atmosphere.”

“One doable state of affairs for the deposition of the tapeworm within the amber is that its elasmobranch host was stranded by a tide or storm.”

“Beneath such a state of affairs, the host was then bitten by a higher-level terrestrial predator or scavenger.”

“When the host was ingested by the predator, the tentacle was pulled away, dislodged from the gut, and caught to close by resin.”

“Our research additional helps the speculation that the Kachin amber was most likely deposited in a paralic paleoenvironment, and likewise highlights the significance of amber analysis in paleoparasitology.”

The workforce’s paper was revealed within the journal Geology.

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Cihang Luo et al. Distinctive preservation of a marine tapeworm tentacle in Cretaceous amber. Geology, revealed on-line March 22, 2024; doi: 10.1130/G52071.1