Hwiccewyrm trispiculum lived during the late Triassic, around 208-202 million years ago, in what is now England. It was one of the last known members of the procolophonid family, a lineage of small stocky lizard-like animals that had been widespread and abundant earlier in the Triassic.
(Traditionally procolophonids are classified as parareptiles, but some recent studies suggest this group is paraphyletic or polyphyletic, with some “parareptiles” potentially nesting within the diapsids instead.)
Measuring around 30cm long (~1′), Hwiccewyrm had wide flaring cheek bones ornamented with large spines, and like some other procolophonids it may also have had bony scute armor on its body. Its large blunt teeth suggest it was feeding on particularly tough foods such as fibrous vegetation or hard-shelled invertebrates.
References:
- Butler, Richard J., et al. “Hwiccewyrm trispiculum gen. et sp. nov., a new leptopleuronine procolophonid from the Late Triassic of southwest England.” The Anatomical Record 307.4 (2024): 1390-1420. https://doi.org/10.1002/ar.25316
- Meade, Luke E., et al. “A new procolophonid with complex dentition from the Late Triassic of southwest England.” Papers in Palaeontology 10.6 (2024): e1605. https://doi.org/10.1002/spp2.1605
- Merck, John. “The Reptilian Stem – A Work in Progress” University of Maryland GEOL 431 Vertebrate Paleobiology, 2025, https://www.geol.umd.edu/~jmerck/geol431/lectures/17sauropsida.html
- Wikipedia contributors. “Hwiccewyrm” Wikipedia, 20 Mar. 2025, https://en.wikipedia.org/wiki/Hwiccewyrm
- Wikipedia contributors. “Parareptilia” Wikipedia, 04 Apr. 2025, https://en.wikipedia.org/wiki/Parareptilia