Every so often I like to feature something here that is only tangentially related to this blog’s primary focus on children’s prehistory literature. Some previous books I’ve reviewed such as Ocean Speaks, Marie’s Ocean, Grand Canyon, God’s Word or Human Reason?, and Unnatural Selection have varying degrees of relevance to paleontology itself, but all of theme at least highlight some important principle that has furthered our understanding of the past.

Bristlecone, by Alexandra Siy and illustrated by Marlo Garnsworthy, primarily focuses on the life cycle of the titular tree, a species renowned for its longevity. The individual known as “Methuselah” was sampled in 1957 and determined to be 4,789 years old at the time. Further exploration has revealed that some of Methuselah’s neighbors are even older, with one topping out at over 5,000 years old!

As the oldest individual organisms in existence, they naturally have significant implications for the study of prehistoric life. The book explains how tree rings form, and shows how environmental conditions affect their formation, telling us much about an individual tree’s history.

Illustrations of rings and core samples from Bristlecone Pine trees. Laypeople are most used to seeing images like the one on the left, but such a sample inherently means cutting the tree down. To preserve a living tree, scientists drill small core samples like those shown on the right, and compare them to each other to establish the series of rings.

While not mentioned directly in the main text, as pointed out in God’s Word or Human Reason?, we can compare the information from the rings of trees both alive and dead to establish a dendrochronology, or a record of years directly written into the wood of the trees. The book does demonstrate the process of comparing core samples taken from an individual tree, and shows how they can be combined to get a complete history of that one tree, but this process can be continued indefinitely by adding samples to the sequence taken from other trees. This technique is limited only by the preservation of the wood itself, as wood will eventually either decay or fossilize, which generally obscures the rings.

We do get to see one brief scene out of prehistory, as the book mentions the changing climates Bristlecone Pines have adapted to since the end of the last Ice Age, and we are treated to an illustration of Bristlecones in a more lowland territory than we see in the modern day, with a ground sloth, a dire wolf, and a teratorn stalking about the ancient forest.

For those looking to get more value out of this book, the publisher’s website has a page titled Web of Life Curricula which offers multiple downloadable PDF worksheets associated with their books, including Bristlecone. Readers can also find projects associated with other books Marlo Garnsworthy has illustrated, like Volcano Dreams: A Story of Yellowstone & The Turtle Dove’s Migration. These have got me curious about the rest of Marlo’s work, and I may look into her free-to-download (via her personal website) solo book Iceberg of Antarctica for some good Antarctic science sometime in the future.

I really liked this book, personally. It has a similar vibe to Jason Chin’s Grand Canyon, and while I’m having trouble precisely defining that certain something, I had nothing but rave reviews for Chin’s book, so I still consider this vague comparison high praise! I had the pleasure of driving through the exact Ancient Bristlecone Pine Forest depicted in this book while on my way to the New Mexico Museum of Natural History and Science last year, so it was fun seeing something so strongly tied to a personal memory depicted in a children’s book. Well-written, and with multiple educational uses, Bristlecone stands as an excellent exploration of the natural world, and I am happy to give it the Dino Dad Stomp of Approval!


  1. Thank you for the great and in-depth review! You mentioned how tree ring chronology using dead wood and living trees can reveal the past back 10,000 years in time. This idea is explored more on my website http://www.Bristlecone with links to other resources! I’m happy you liked the book!


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