🪐 View in 3D Galaxy 📏 View on 3D Scale Stage

🧬 Biological Classification (Kingdom to Species)Nacospatangus altus

Kingdom

Animalia

Phylum

Echinodermata

Class

Echinoidea

Order

Spatangoida

Family

Maretiidae

Genus

Nacospatangus

Species

Nacospatangus altus

📏 True-scale comparison (1 m = 1 m) against a 1.75 m humanLength 3.3~4.7cm

🔍 Zoomed View — Same scale as a credit card & 2.65cm coin

· 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.
· Nacospatangus altus: Drawn using our own body-shape diagram where an open-licensed silhouette was unavailable.
· Human silhouette: PhyloPic — NASA · Public Domain Mark 1.0

• Length vs. 1.75 m human: 0.02× Compare with other species →

Echinoidea❔ Diet unknown

Nacospatangus altus

Nacospatangus altus (Nacospatangus altus · Nacospatangus altus)

🛡️ Conservation Status (IUCN Red List)NE (Not Evaluated)

Not Evaluated (NE) on the IUCN Red List yet.

🇰🇷 Class II endangered wildlife (Korea)

Geological Era

Extant

Diet

No data

Length · Height

3.3~4.7cm · No data

Mass · Top Speed

No data · No data

Habitat & Fossil Locality

Shallow marine sandy bottoms in the Indo-West Pacific (recorded at depths of 1.5–204 m; sandy bottoms between coral reefs at 20–30 m in Sri Lanka)

💡 Everyday Comparisons for Size, Mass & Speed

💡 Its maximum test length of about 4.7 cm is slightly shorter than the short side of a credit card (5.4 cm) (Comparison).
💡 Since its width is 73–80% of its length, a test 4.7 cm long is about 3.4–3.8 cm wide, which is wider than the diameter of a Korean 500-won coin (2.65 cm) (Comparison).

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.

#의염통성게#Nacospatangus altus

📖 1. Overview

Nacospatangus altus is a heart urchin known from western Indian Ocean islands to the Philippines, China, and southern Japan, with a thin and fragile test.

🦴 2. Anatomy & Morphology

Its test (skeleton) is thin and fragile; its width is 73–80% of its length, and its highest point is a sharp ridge toward the rear. The underside is flat, and below the anus there is a heart-shaped band (fasciole).

🔍 3. Ecology & Behavior

It has been recorded at depths of 1.5–204 m from western Indian Ocean islands across to the Philippines, China, and southern Japan. In Sri Lanka, it was collected from sandy bottoms between coral reefs at depths of 20–30 m.