Jurassic Pets

Jurassic Pets: Owning a Real-Life Relative of Prehistoric Creatures

The trilobite is one of the best-known animals from the explosion of life in the Cambrian period. Their fossils are relatively easy to get hold of, and most geologists can tell you more than you ever wanted to know about these multi-segmented little creatures.

Sadly, you'll never be able to own a trilobite. The Permian mass extinction 251 million years ago was the end for the multitude of trilobite species. But there's something else still wandering around Earth that gives you something properly close to the same experience — and you can get them for far less than the price of a decent fossil.

I'm talking, of course, about isopods.

The Trilobite Connection (Honestly)

Let me be honest about this up front. Isopods and trilobites aren't close relatives. They're both arthropods (the broader group containing insects, spiders, crustaceans, and trilobites), but they sit in different sub-branches of the family tree. Trilobites belong to their own extinct subphylum (Trilobitomorpha); isopods are crustaceans, properly closer to crabs than to anything else.

What they do share is a similar look and feel:

• Segmented bodies
• Hard exoskeletons
• Multiple pairs of legs
• A general "armoured pillbug" silhouette
• The ability to roll into a defensive ball (in many trilobites; in conglobating isopods like Armadillidium)

If you want the visual experience of keeping something that looks like it crawled out of deep prehistory, isopods are the closest living analogue you'll find at this scale.

How Old Are Isopods, Really?

Isopods as a group are properly ancient. The first identifiable isopod fossils date from the Carboniferous period — around 300 million years ago. That's significantly older than the dinosaurs.

For most of their history, isopods were marine creatures — the giant deep-sea Bathynomus we see today is closer to the ancestral form than the woodlice in your garden. Terrestrial isopods (the order Oniscidea, which contains all the species we keep as pets) are a properly more recent development. The earliest fossil evidence for land isopods comes from much later than the marine forms — the colonisation of land was a major evolutionary transition that took place gradually over millions of years.

So while isopods as a group were definitely around during the Jurassic, the specific kind you'd keep as a pet — the terrestrial woodlice and pillbugs — only became truly established on land much later. The dinosaurs would have known marine isopods properly well; the modern garden pillbug is a much more recent invention.

That said, the isopod body plan is fundamentally Mesozoic. When you watch your Cubaris or Armadillidium shuffle around their enclosure, you're watching a body plan that has worked, with relatively minor variations, for hundreds of millions of years.

What Is an Isopod, Anatomically?

Isopods are crustaceans — properly more closely related to crabs, lobsters, and shrimp than to insects. The order Isopoda is huge and diverse: from the tiny cute Cubaris on the gentle end of the spectrum to the deep-sea Bathynomus on the dramatic end. (Yes, the giant isopods that occasionally make headlines for being filmed eating dead sharks on the deep-sea floor — they're properly scavengers rather than predators, but it's still genuinely impressive footage.)

All isopods share certain features:

• Two pairs of antennae — first antennae (smaller) and second antennae (larger, more visible)
• Multiple feeding appendages — mandibles, maxillae, and maxillipeds work together to process food
• Compound eyes — like flies and wasps, they can't see fine detail the way we can, but they can detect movement properly well, and they can see polarised light. That's a kind of light filtering that humans can't normally perceive — they're seeing things we'd need specialist equipment to detect
• Seven-segmented thorax (pereon) — each segment carries one pair of walking legs, giving the characteristic seven pairs of legs that define the order
• Abdomen (pleon) — made up of segments called pleonites, ending in a fused terminal section called the pleotelson
• Pleopods (limbs on the pleon) — used for swimming in aquatic isopods, and for respiration. Terrestrial isopods have evolved specialised air-breathing structures called pseudotracheae in their pleopods, which let them exchange gas without needing to be submerged in water

That gas-exchange adaptation is one of the most genuinely interesting features of terrestrial isopods. They're still essentially aquatic animals that evolved to live on land — they need humidity, they prefer damp microenvironments, and they breathe through what are properly modified gills.

The Best Unusual Pet

Isopods give you something properly close to a Jurassic Park experience in a tiny enclosure that will fit comfortably on your desk or table. Even better — if something goes wrong, you don't have to run for your life.

The prehistoric aesthetic isn't just marketing. Watching a colony of Porcellio or Cubaris potter around their terrarium genuinely is watching ancient body plans in motion. The way they move, the way they hide under bark, the way they conglobate when threatened — all of this would have looked familiar to a creature observing isopods 50, 100, or 200 million years ago.

Setting Up a Prehistoric Terrarium

Once you have the basic care needs sorted (see our guide to setting up and selecting your first isopods), the aesthetic is properly up to you.

If you want to lean into the Jurassic theme — go for it. A mini set of Jurassic World gates? A model T-Rex stalking the leaf litter? A miniature ranger station made of cocktail sticks? Your enclosure, your imagination.

But even without the obvious dinosaur props, a planted prehistoric-feeling terrarium can be properly atmospheric. Many of the plant groups that thrive in isopod enclosures are themselves ancient — ferns, lycophytes (club mosses), and bryophytes (true mosses) were all dominant land plants during the Carboniferous and Jurassic. Building a planted enclosure with these is genuinely a window into deep botanical history.

Plants for a Prehistoric Terrarium

Two of my favourite plants for adding greenery:

• Boston Fern (Nephrolepis exaltata) — the dwarf or compact varieties work better for small terrariums. Ferns are properly ancient — the lineage extends back over 360 million years
• Asparagus fern (Asparagus setaceus and A. densiflorus) — not technically ferns despite the name, but they have that delicate fronded look. Depending on the size of your terrarium, both can form the backdrop to your planting

For midground and foreground:

• Martens club moss (Selaginella martensii) — lovely fern-like fronds and a creeping habit that fills gaps in any planting. Club mosses (Lycopodiophyta) are properly one of the most ancient land plant lineages, with origins around 400 million years ago. They were dominant during the Carboniferous when isopods first appeared. Just make sure you leave some space so you can actually see your isopods as they explore

For higher-humidity setups or terrariums with water features:

• Bucephalandra — commonly sold for aquariums, but in the wild they grow near waterfalls and are typically cultivated emersed (out of water) before being submerged. If you buy one pot from an aquatics shop, you can often tease apart three or four separate plants. They don't like having their roots in soil — use a touch of super glue (or aquarium-safe glue) to attach the roots to a piece of wood or rock. Keep their roots wet or spray them regularly

For substrate-level coverage and humidity retention:

• Sphagnum moss — patches in corners create localised humidity refuges. Properly authentic in a prehistoric setup — bryophytes are among the oldest land plants on Earth
• Hardwood leaf litter — not strictly a "plant" anymore, but oak, beech, magnolia and similar leaves replicate the kind of decomposing forest floor isopods evolved to thrive in. Browse our leaf litter for ready-prepared options

Choosing Your Isopods

Here's the question that matters most: after all that time, effort, and yes — money on building your terrarium, what do you actually put in it?

For a Jurassic-feeling display, I'd genuinely suggest:

• Larger Porcellio species — our Porcellio collection includes substantial Spanish species like Porcellio magnificus with proper armoured appearance. They have the size and the prehistoric aesthetic
• Cubaris morphs — premium tropical isopods from limestone cave systems in Southeast Asia. The cave environments give them a properly otherworldly feel. Browse the Cubaris collection — Rubber Duckies, Panda Kings, and similar species look genuinely alien in a planted setup
• Larger Armadillidium — for conglobating "rolly polly" behaviour that genuinely echoes how trilobites used to defend themselves. The Armadillidium collection includes plenty of options
• Dairy Cow Isopods (Porcellio laevis) — prolific, hardy, and properly visible in the enclosure. Their black-and-white pattern looks striking against green planting

For a properly authentic prehistoric-themed setup, mix species carefully — some combinations breed unwanted hybrids or compete badly. Stick to one species per enclosure if you want to maintain genetics, or accept some uncertainty if you're prioritising aesthetics.

Bringing It All Together

Build the planted base. Add the wood and bark. Layer in the leaf litter. Position your miniature dinosaur (if you're going there). Add your isopods. Watch a tiny slice of deep prehistory come alive on your shelf.

For everything you need to set up — substrate, leaf litter, cork bark, lotus pods, calcium sources, and the isopods themselves — browse our accessories collection and species pages. The little guys have been doing their thing for hundreds of millions of years. Properly worth giving them a good home for a few of those.