- · Grid units represent actual meters (m); human and animals are drawn to the exact same scale with original silhouette aspect ratios preserved.
- · When a size range is recorded (e.g. 1–1.6m), the lower bound is used for scale comparison.
- · Hallucigenia: Drawn using our own body-shape diagram where an open-licensed silhouette was unavailable.
- · Human silhouette: PhyloPic — NASA · Public Domain Mark 1.0
Hallucigenia
Hallucigenia sparsa (Hallucigenia · Hallucigenia)
Known only from fossils. The IUCN Red List assesses only species extant since 1500 CE, so fossil taxa are not assigned a category.
💡 Everyday Comparisons for Size, Mass & Speed
- 💡 A maximum body length of about 35 mm is about 1.3 times longer than the diameter of a Korean 500-won coin (26.5 mm) (Comparison).
- 💡 Research findings showing that its claw structure is identical to that of modern velvet worms (onychophorans) were featured in a University of Cambridge press release.
Reference standards: coach bus ~12 m, mid-size car ~4.9 m, compact car ~1 t, basketball hoop 3.05 m, credit card 8.56 cm.
📖 1. Overview
Hallucigenia sparsa (genus Hallucigenia) was a worm-like animal that lived in Cambrian seas about 505 million years ago and was found in the Burgess Shale of Canada. It has been shown to be a distant relative of modern velvet worms (onychophorans).
🦴 2. Anatomy & Morphology
A single row of stiff spines ran along its back, and each of its seven to eight pairs of legs ended in claws. In the past, it was interpreted upside down and backward, with its spines mistaken for legs and its head for its tail.
🔍 3. Fossil Record & Paleoecology
Because the stacked cone-in-cone structure of the cuticle layers in its claws matches that of modern velvet worms, researchers placed it in the velvet worm lineage on that basis. The Burgess Shale is one of the richest Cambrian fossil sites.
🇰🇷 4. Connection to Korea
No direct record connecting this species to Korea has been found.
📚 Sources & References
- • Fossil taxon — the IUCN Red List assesses only species living or extinct since 1500
- • paleobiodb.org — basicTaxonInfo
- • wikidata.org — Q10293595
- • commons.wikimedia.org — File:HallucigeniaSparsa-ROM-June11-10.jpg
- • cam.ac.uk — misunderstood-worm-like-fossil-finds-its-place-in-the-tree-o
- • rom.on.ca — 9800
Recorded dimensions are widely cited representative estimates from public literature and may vary by study or specimen.