Haplophrentis reesei / Bythicheilus typicum

Haplophrentis reesei is an extinct, enigmatic, tubular fossil known from the Cambrian period, particularly from the Burgess Shale and similar Konservat-Lagerstätten. Its long, slender, and slightly tapering cone-shaped shell, composed of stacked, calcareous plates, has puzzled paleontologists for decades. While its exact phylogenetic placement remains debated, recent studies have suggested affinities with the hyoliths, a group of extinct, cone-shaped animals with a distinctive operculum. Haplophrentis likely lived a benthic, possibly sessile, lifestyle, filtering food particles from the water column. Its unique morphology and the challenges it poses to classification make it a fascinating subject of study for understanding the diversity and evolution of early metazoan life.

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Reference to Wikipedia: Haplophrentis