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Fossils aren’t your forte? A charming tale of cephalopod evolution may change your mind

Squid Empire: The Rise and Fall of the Cephalopods

Danna Staaf
ForeEdge
2017
253 pp.
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As a squid biologist, I have always been a huge fan of living cephalopods, but their shelled ancestors never piqued my interest before I picked up Danna Staaf’s Squid Empire. Thanks, in part, to her unbridled enthusiasm, by the end of the book, I found myself actively rooting for animals that I had previously only thought about as fossils.

Early cephalopods used horn-shaped chambered shells to control their buoyancy, allowing them to bob and float above the seafloor. The resulting mobility allowed them to evade predators and capture prey. With an abundant amount of food available and a lack of competition, cephalopods flourished, growing to enormous sizes. (Fossils as long as 3.5 meters dating from the Ordovician have been discovered in Iowa.)

Cephalopod evolution is a fantastic subject for lovers of drama: The moment the protagonist appears to be done for, a narrow escape ensues. When fishes developed jaws, cephalopods countered with beaks. When fishes became faster swimmers, cephalopods traded their shells for speed and got better at hiding with dynamic camouflage.

In chapter 4, Staaf delves into the radiations of the now-extinct ammonites, colorfully describing the ornate and elaborate shells that these organisms left behind. Ammonites were one of the most successful animals of their time, and the diversity of their fossils is used by paleontologists to answer questions about how new species arise.

As one of the most abundant fossil types discovered by humans, ammonites have taken on symbolic meaning in various cultures. Legends passed down by the Blackfeet Indians, for example, refer to these small fossilized tokens as “buffalo stones.” They were believed to bring good fortune to those who found them.

Although the title of the book is hardly inaccurate, Staaf really examines the rise, fall, and current comeback of the cephalopods, because these adaptable creatures are by no means decreasing in the oceans today. If anything, they are doing better than many other organisms, thanks to their ability to thrive in warming oceans and the widespread overfishing of their trophic-level peers.

The book concludes with a who’s who of modern day cephalopods. From the half-ton colossal squid to the 7-centimeter dwarf cuttlefish, cephalopods live in nearly every corner of the ocean and represent a wide array of lifestyles.

SUBAQUEOSSHUTTERBUG/ISTOCKPHOTO

Despite their small size, blue-ringed octopuses pack a dangerous punch, having evolved a venom that contains a deadly neurotoxin.

Despite the monstrous size of some squid and the fearsome legends of the giant kraken, few human deaths have been recorded from cephalopods. In fact, according to Staaf, every recorded fatality from a cephalopod can be traced back to the candy-colored, golf ball–sized blue-ringed octopus, whose venom contains a powerful tetrodotoxin—the same paralytic chemical that permeates the puffer fish (not exactly the vicious Cthulhu you might imagine).

Staaf’s enthusiastic approach to cephalopods should come as no surprise: She trained in the laboratory of William Gilly at Hopkins Marine Station, where squid prints adorn every wall and you can’t go 5 feet without a papier-mâché tentacle or fin dangling above your head. It is a treat to come across a writer with such specialized training who is able to turn esoteric knowledge into a page-turning read for all audiences.

Her playful tone made me laugh out loud several times—for example, when she described the scientists responsible for piecing together cephalopod histories from rock fragments and fossils. “[W]hat are these people doing? Just coming up with crazy ideas all the time?” asks an exasperated paleontologist at one point, throwing scientific shade at those who speculate that enormous unshelled cephalods once roamed the ocean, feasting on 50-foot ichthyosaurs. Elsewhere, another researcher bemoans his own graduate school experiments as “one of the most atrocious things” he’s ever done.

In these scenes, Staaf captures what is rarely seen outside the ivory tower: scientists talking among themselves with a touch of irreverence. Researchers everywhere will surely relate.

About the author

The reviewer is at the Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA.