Eldredgeops: No measured body size data available to draw at scale.
- · 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.
- · Human silhouette: PhyloPic — NASA · Public Domain Mark 1.0
Eldredgeops
Eldredgeops rana (Eldredgeops · Eldredgeops)
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
- 💡 Some lenses of this eye type measured 2 mm or more in diameter, meaning its eyes were set with multiple large lenses about as thick as a grain of rice (Comparison).
- 💡 Whereas the eye parameter of living arthropods is about 0.1 for diurnal species and about 20 for nocturnal or deep-sea species, values from 10 to over 150 have been reported for subspecies of this species, exceeding any living animal (cited from a PMC paper).
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
Eldredgeops rana is a trilobite that lived in North American seas during the Devonian and was formerly called Phacops rana. It belongs to the phacopid group, famous for its large, distinct eyes.
🦴 2. Anatomy & Morphology
It had special compound eyes (schizochroal eyes) in which large lenses were arranged at wide intervals within each eye. Such phacopid eyes are interpreted as a "compound eye within a compound eye" structure, with a tiny compound eye beneath each lens.
🔍 3. Fossil Record & Paleoecology
Studies of the distribution of its sensory tubercles suggest that it moved actively on the sea floor and could obtain food in two ways. In studies of eye performance, two subspecies showed higher eye parameter values than any living arthropod.
🇰🇷 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
- • commons.wikimedia.org — File:Phacops rana.jpg
- • pmc.ncbi.nlm.nih.gov — PMC8484558
- • cambridge.org — 5AAC6E5F439ED6ED93BE18424EBF61FA
Recorded dimensions are widely cited representative estimates from public literature and may vary by study or specimen.