Meet the frilled shark, an 80-million-year-old deep-sea survivor from the dinosaur age

Frilled shark (Image: Canva)

The frilled shark is a rare deep-sea predator with ancient features and mysterious habits. Living in dark, hostile depths, it hunts with stealth, reproduces slowly, and preserves traits unchanged for millions of years, making conservation crucial.

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Scientists are renewing attention on the frilled shark, a rarely seen deep-sea predator whose unusual anatomy and ancient lineage continue to challenge understanding of ocean life and evolution.

Hidden far below sunlight, the deep ocean shelters species rarely encountered by humans. Among them is Chlamydoselachus anguineus, commonly known as the frilled shark. Although identified more than a century ago, the animal remains poorly understood. Researchers still lack clear answers about its lifespan, breeding cycles, and hunting behaviour. Most encounters occur accidentally, when fishing nets reach extreme depths. These rare moments provide scientists brief insight into a creature shaped by stable, hostile environments.

Frilled shark anatomy reveals ancient survival design

Frilled sharks usually reach around 2 metres in length. Their bodies are long and cylindrical, resembling eels more than typical sharks. The dorsal fin sits unusually close to the tail. This shape allows movement through tight, rocky spaces. The skin is relatively smooth, reducing resistance in deep water.

The head carries the shark’s most striking features. It has 6 gill slits, unlike most sharks. These gills form a frilled collar beneath the throat. Scientists believe this structure improves efficiency in oxygen-poor depths. The mouth is wide, lined with trident-shaped teeth. These teeth grip soft, slippery prey with ease. The flexible jaw enables swallowing prey whole, including large squid.

Feeding habits shaped by deep ocean conditions

Frilled sharks sit near the top of deep-sea food chains. Studies show diets dominated by squid. They also consume fish and smaller sharks. Rather than speed, they rely on stealth. Their snake-like bodies allow sudden strikes from concealment. This hunting style suits dark environments where energy conservation matters. Such adaptations reflect millions of years spent in low-light conditions.

Reproduction, rarity, and conservation concerns grow

Frilled sharks reproduce through ovoviviparity. Embryos develop inside the mother before birth. Young are sustained by yolk sacs early. Gestation length remains uncertain, possibly lasting several years. This slow cycle limits population recovery. It also explains why sightings are uncommon.

Often called living fossils, frilled sharks resemble ancient relatives from 80 million years ago. Fossil records show similar shapes and behaviours. However, modern frilled sharks are not unchanged copies. Instead, they represent evolutionary stability within unchanging environments.

Scientists warn that deep-sea fishing and environmental disruption pose risks. With slow reproduction, populations may decline unnoticed. Researchers stress their ecological role as deep-water predators. Protecting such species supports the health of largely unexplored ocean ecosystems.