Seals, sea lions, and walruses are all pinnipeds—marine mammals adapted to life in the ocean with streamlined bodies, flippers, and excellent swimming ability. Because they look somewhat similar at a glance, people often confuse them. However, they differ clearly in taxonomy, ears, movement on land, size, diet, and behavior.
Taxonomy
All three belong to the pinniped group (often treated as a clade within Carnivora), but they split into different families:
True seals: Family Phocidae
Sea lions (and fur seals): Family Otariidae
Walrus: Family Odobenidae (one living species: Odobenus rosmarus)
These evolutionary differences help explain why their bodies and lifestyles aren’t the same.
Physical Differences
1) Tusks
Walruses are the easiest to identify because they have long tusks (elongated canine teeth) that can reach impressive lengths.
Seals and sea lions do not have visible tusks like a walrus.
2) Ears
Sea lions have visible external ear flaps (small “ears” you can see).
True seals do not have visible ear flaps—only small ear openings.
Walruses also do not have visible ear flaps.
This is one of the fastest field marks: ear flaps = sea lion.
3) Front flippers and movement on land
True seals (Phocidae)
Front flippers are relatively short.
They cannot rotate their hind flippers under their body to walk.
On land they typically wriggle or “inch” forward with a belly-and-side movement.
Sea lions (Otariidae)
Front flippers are longer and powerful.
They can rotate their hind flippers forward and walk on land using all four limbs.
They look much more agile and “dog-like” when moving on shore.
Walruses (Odobenidae)
Can also bring their hind flippers forward to support their body on land.
They move heavily but more “upright” than true seals.
4) Size
Size varies a lot by species—especially among seals and sea lions.
Sea lions: range from relatively small species to very large ones (some can approach a ton in mass).
Seals: range from smaller coastal seals to giant species (the largest seals can reach several tons).
Walruses: generally very large and heavy-bodied, commonly around 1–2 tons for adults, depending on sex and population.
In simple terms: walruses are usually the heaviest-looking, while seals and sea lions vary widely.
5) Head and face shape
Walrus: broad muzzle, extremely noticeable whiskers (vibrissae), and a distinctive “bulldog” face with tusks.
True seal: generally rounder head and shorter-looking snout; many have a softer, more “compact” facial profile.
Sea lion: longer, more dog-like muzzle and a more pronounced neck and chest.
Habitat
Seals
Found from polar regions to temperate and even some warmer waters, depending on species.
Many species tolerate ice habitats well and may haul out on pack ice.
Sea lions
Also widespread, but many species prefer temperate coasts and are commonly seen on rocky shorelines and beaches.
In general, sea lions are more associated with ice-free haul-out sites.
Walruses
Strongly associated with the Arctic and subarctic.
Often depend on sea ice platforms for resting between feeding trips.
Diet
Walruses: benthic specialists
Walruses are strongly linked to the seafloor. Their sensitive whiskers help them detect prey buried in sediment, and they feed mainly on benthic animals such as:
Clams and other mollusks
Crustaceans
Other bottom-dwelling invertebrates
Seals and sea lions: active hunters
Most seals and sea lions mainly hunt in the water, often targeting:
Fish
Squid
Other marine animals depending on the species and region
Sea lions, with their better mobility on land and highly social behavior, may also exploit coastal opportunities more flexibly in some areas (for example, preying on seabirds in certain situations).
Behavior
Vocalizations
Sea lions are famous for loud barking and intense noise at breeding colonies.
Seals often produce grunts, growls, and other calls, but many are less “bark-like.”
Walruses use grunts, bell-like sounds, and various vocalizations, especially in social groups.
Social life and group size
Sea lions often form large, noisy colonies and have clear social structures in breeding season.
Walruses can gather in very large haul-outs, especially around feeding areas and ice edges, also with social dynamics.
Seals range from solitary to moderately social depending on species; many are less group-oriented than sea lions.
Quick Identification Guide
Visible ear flaps? Yes → Sea lion
Long tusks + huge whiskered muzzle? → Walrus
No ear flaps + moves by wriggling on land? → True seal
