Bizarre Taxonomy 'Facts'

When Similarity Misled Science: Bizarre Groupings in Early Taxonomy

In the golden age of natural history, the desire to classify all living things often led early scientists down unexpected, and at times, wildly inaccurate, paths. Lacking the genetic tools we rely on today, 16th- and 17th-century taxonomers grouped animals based on superficial features such as shape, texture, or behavior. These visual and functional similarities resulted in some of the most fascinating and peculiar errors in scientific classification.

Here are some of the most bizarre, and entertaining, examples of how appearances deceived even the greatest minds of early taxonomy:

1. Bats Were Classified as Birds Because they flew, bats were naturally assumed to be birds. Their leathery wings didn’t raise many red flags at the time, and details like fur, teeth, and live birth were overlooked. It wasn't until much later that bats were correctly identified as mammals.

2. Whales and Dolphins Were Called Fish Even Carl Linnaeus himself, father of modern taxonomy, initially grouped cetaceans like whales and dolphins with fish due to their streamlined bodies and aquatic lifestyle. Despite breathing air and nursing their young, their fish-like form took precedence in early classification.

3. Chameleons Were Grouped with Snakes Chameleons were mistakenly associated with snakes and lizards in the broader category of "serpents." Why? Their scaly skin and elongated bodies were enough for early naturalists to lump them together, never mind the legs, tongue, or independently moving eyes.

4. Slugs Were Deformed Snails Slugs, being essentially snails without shells, were sometimes considered defective or incomplete snails. Rather than understanding them as a separate lineage of gastropods, early scientists assumed they were what happened when nature “forgot the shell.”

5. Flying Fish Were Almost Birds The flying fish's ability to leap from the water and glide through the air with its extended pectoral fins had some scholars placing it in awkward proximity to birds. Some illustrations even depicted them mid-flight with exaggerated wings, calling them "sky swimmers."

6. Turtles and Armadillos Shared a Category Due to their hard protective shells, turtles and armadillos were once linked in classification systems. While today we know one is a reptile and the other a mammal, the early emphasis on body armor overshadowed all other anatomical differences.

7. Peacocks and Lobsters Were Compared for Their "Fans" The extravagant tail feathers of peacocks and the spread of a lobster’s tail or antennae led to comparisons between the two. Some symbolic groupings united these creatures based purely on the aesthetic flourish of their body parts.

8. Humans and Apes with Four-Legged Beasts Before a clearer understanding of primate evolution, humans and great apes were sometimes listed with four-legged mammals such as bears or big cats. Shared body hair and skeletal similarities were noted, but behavioral and cognitive traits were often ignored.

9. Onions and Sea Anemones Confused by Structure Strange but true, some early comparisons were drawn between onions and soft-bodied sea creatures like jellyfish or anemones, based on their concentric ring structure and squishy consistency. The confusion didn’t last long but reflects how surface-level traits misled classification.

10. Worms, Snakes, and Legless Lizards Lumped Together The logic went like this: no legs = same thing. This led to earthworms, eels, snakes, and even legless lizards being grouped under the same umbrella category. Only with later anatomical and behavioral studies did these distinctions become clear.

How Far We've Come: The Linnaean Legacy Carl Linnaeus, who published his landmark Systema Naturae in 1735, believed there were likely no more than 10,000 species of plants on Earth. Today, scientists have identified over 350,000 plant species, and many botanists believe that number represents less than half of the true diversity. Thanks to molecular biology and DNA sequencing, we now understand that similarity in form doesn’t always mean close relation.

What these early efforts show is the power, and the peril, of assumption. They remind us that science is a journey, not a destination, and even mistakes have value when they open the door to deeper understanding.

Would you wear a shirt featuring one of these “Misclassified Creatures”? Check out our ocean-inspired collections that celebrate the curious beauty of nature, both correctly and incorrectly understood.