The Evolution Underground – Part 2: Behind the Scenes

“I still don’t understand why they were looking for alligator dens.”

My dad and I had been discussing the review I’d written about Dr. Anthony Martin’s latest book, “The Evolution Underground.”  He voiced this confusion with more concern for the overall safety (and perhaps sanity?) of the Emory professor and his students than an interest in what knowledge they hoped to gain.

To be fair, my dad hadn’t yet read this or any book about ichnology and was not familiar with the field.  My inability to make that part of the book clearer aside, it also spoke to a question I’d had this past December.  Speaking with him by phone, I asked Dr. Martin: Did he think more people know about ichnology as a result of his prolific work?

“I think,” he began thoughtfully, “through the books, [through] giving public talks, and [by blogging] about it, I’m fairly confident in saying, ‘yes, more people are more aware now of ichnology as a science.’ I think that ‘Dinosaurs Without Bones’ was a really good step [toward] popularizing ichnology as science, and then I think that ‘The Evolution Underground’ will take it another step further.”

Dr Anthony Martin courtesy of Carol Clark

Image of  Dr. Anthony Martin, courtesy of Emory University 

It is telling that, of the four books Dr. Martin has written so far, three of them focus on ichnology.  His handle on Twitter is @ichnologist.  Most of his blog posts feature concepts related to ichnology.  During our conversation, he chuckled and admitted he refers to himself as an “ichno-evangelist.”

Any physical remnant of an extinct or extant creature falls into ichnology: bites, scratches, footprints, marks indicating the drag of a tail, coprolites or scat.  Reading those traces—recognizing them for what they are—is a skill, and one for which there are relatively fewer reference points than the much older field of paleontology.*  Dr. Martin explains this in his first work with Pegasus Books, “Dinosaurs Without Bones.”  It is one thing to see a fossil femur, for example, and understand what it is.  Recognizing a fossil nest, however, or a fossil burrow, is considerably more challenging.  Without “search images” or reference points that help other scientists understand what to look for, such fossils might be easily missed.

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Detail of a slab of fossil footprints surrounded with what are believed to be fossil raindrops at the Beneski Museum at Amherst College, Massachusetts. Both the footprints and the raindrops are examples of ichnology. Picture taken by the author of this blog.

 

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Can you tell what these are? I can’t, and, so far, neither can the experts.  As-yet unknown trace fossils at the Beneski Museum at Amherst College, Massachusetts; pictures taken by the author of this blog.

Figure 1: A brief summary of animal burrowing through time, from the Ediacaran Period through today.  Geologic eras on left, periods on right, MYA = millions of years ago, and red arrows indicate times of mass extinctions in the geologic past. (Image and caption used with permission from Pegasus Books)

 

“Sage scents wafted by on the wind and, in between scoops, I looked around at the nearby pine forests and rolling, high-plains grassland nearly everywhere else, then up at an expansive blue sky hosting white, fluffy clouds.  You might say I was in a country where the sky was big: Some people just call it ‘Montana.’” – page 87, “The Evolution Underground: Burrows, Bunkers, and the Marvelous Subterranean World Beneath Our Feet,” by Dr. Anthony J. Martin, Pegasus Books

In the book, Dr. Martin describes participating in an excavation in the Blackleaf Formation that lead to the discovery of the first known fossilized burrow, found collectively by Dr. Martin, Yoshi Katsura, and Dr. David Varricchio of Montana State University.

This discovery—based solely on noticing the odd structure of sediment surrounding bones—is no small feat.  Looking at an image of this burrow, which you can see in Dr. Martin’s blog post here, I am amazed that anyone would be able to decipher what it actually is when working through layers of other rock, let alone when it was completely revealed.

Dr. Martin credits his mentor and former professor, Bob Frey, with guiding him in ichnology.  Both Dr. Varricchio and Dr. Martin were fellow students in his class, a class that seems to have been a road map for both of them in their future discoveries.

And while in this book Dr. Martin discusses many extant burrowers, he certainly addresses those found in the fossil record as well.

Figure 38: Early Cretaceous (130 mya) lobster burrow preserved as natural cast on bottom of limestone bed, Portugal.  Although the lobster’s body is not preserved, its leg impressions and body outline were left behind.  (Photo by Anthony J. Martin; image and caption used with permission from Pegasus Books)

The bigger picture behind these everyday observations of many holes in the ground, however, is that the long history of these burrowing invertebrates completely altered global environments, from the deepest sea to the highest mountains, and even affected the atmosphere and climate.  In short, the entire surface of our planet is built upon one big complex and constantly evolving burrow system, controlling the nature of our existence.” — page 14, “The Evolution Underground: Burrows, Bunkers, and the Marvelous Subterranean World Beneath Our Feet,” by Dr. Anthony J. Martin, Pegasus Books

 

The quote above is the central theme of “The Evolution Underground.”  I wondered if he’d gained this perspective after completing the book, or if this was something he carried as he began writing.

“I did go in with that big picture idea about burrows having this overarching influence on all of our ecosystems,” he replied. “[That, we, too,] have this evolutionary heritage that [is] connected to burrows. So I did have that idea in mind, but it was really scattered. Really disparate.  Also, it wasn’t an original idea. Lots of other people really deserve credit for that, [and they are] cited in the endnotes of the book.

But, he said, “[w]riting the book definitely helped me pull together a lot of those previously separated ideas into the theme that I summarized as ‘burrows acting as the midwife in the birth of Gaia.’

“We can’t really talk about the evolution of ecosystems or the evolution of life without talking about burrows.”

Figure 16: Folk-art rendering inspired by the Lystrosaurus saga set during the Permian-Triassic transition (Chapter 5), with a cutaway view of a Lystrosaurus burrow. (Artwork by Ruth Schowalter and Anthony J. Martin; image and caption used with permission from Pegasus Books) — (The author of this blog wants to note, as Dr. Martin does in the endnotes, that his interest in the species was inspired by this piece by Annalee Newitz.)

Having written four books, did writing them get easier?

“It did get easier with each book,” he acknowledged. Then laughed. “But, of course, the word ‘easy’ is relative.”

“[‘The Life Traces of the Georgia Coast‘] was hard to write because it was so comprehensive.  It was almost 700 pages long; it had more than 800 peer-reviewed references. It’s an academic book, but I [also] wrote it for a popular audience.  So it’s a hybrid kind of book in that respect. That took four years from the acceptance of the book proposal to actually holding it in my hands.”

“And,” he added, “a book is not finished until I’m holding it in my hands.”

“In contrast to that, ‘Dinosaurs Without Bones’ was quick. That took me—from start to end—less than two years. I felt like [‘The Evolution Underground’] was a little bit easier than ‘Dinosaurs Without Bones,’ but that’s only because I used Pegasus Books again as the publisher. And I had the same editor: Jessica Case. With that said, it was still difficult to write because it covered so many different burrowing animals, [not to mention it covered] the last 560 million years!

“The main takeaway point of it is for people to better appreciate the world they don’t often see, and that’s the world below their feet. We might not even be here talking about burrowing animals if our earliest mammalian ancestors hadn’t burrowed.”

 

*This comment is not meant to hold one field over another. I have great respect for the skills needed for both paleontology and ichnology.

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Thank you to Carol Clark, Senior Science Communicator at Emory University, for the wonderful picture of Dr. Martin!

A sincere and enthusiastic THANK YOU to Dr. Anthony Martin for his willingness to connect by phone and for his generous responses to my questions!  It was a pleasure and an honor to be able to speak with him, and—like his writing—he made it fun!  I eagerly (if impatiently) await any possible future work.  

FULL DISCLOSURE: The author of this blog loved Dr. Martin’s previous book with Pegasus, “Dinosaurs Without Bones,” and thus, jumped at the chance to review his latest work (fully predisposed to embrace it) by requesting a review copy from the publisher.  I am very grateful to Pegasus Books for the opportunity to do so. Being able to use such beautiful images from the book is a great honor! I am specifically grateful to Deputy Publisher, Jessica Case, with whom it was wonderful to work!!

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References:

  1. The Evolution Underground: Burrows, Bunkers, and the Marvelous Subterranean World Beneath Our Feet, Anthony J. Martin, Pegasus Books, 2017
  2. Dinosaurs Without Bones: Dinosaur Lives Revealed by Their Trace Fossils, Anthony J. Martin, Pegasus Books, 2014
  3. Life Traces of the Georgia Coast Blog, Anthony J. Martin

Evolution Underground

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The Evolution Underground – Part 1: Book Review

Not all scholars write with the playfulness or the open curiosity found in books written by Dr. Anthony Martin, professor at Emory University.

In his second work with Pegasus Books, “The Evolution Underground: Burrows, Bunkers, and the Marvelous Subterranean World Beneath Our Feet,” he opens with an anecdote about an outdoor class on an island off of the Georgia coast.  If you have any question about whether this book is for you, read those first several pages.

He, his colleague, Michael Page, and several students were mapping alligator dens.  While they’d witnessed many active dens from a safe distance, in this instance, they were exploring those long abandoned by their former occupants.  They were, he explained to the reader, in the middle of the forest where a now-nonexistent canal once ran.  Without water, there would, of course, be no alligators.

Only he was wrong.  And this was pointed out when a student noticed teeth within the den.

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Picture of alligators by Michael Leggero, courtesy of Getty Images

You will need to read the book to find out what happens, but this first chapter perfectly encapsulates how Dr. Martin writes. If you want to learn about any aspect of our world from a scientific and curious lens, here is an author you might want as your guide.  He is no stranger to presenting enormous volumes of information in an easily digestible way, nor is he one to make it cumbersome. His wit and sense of adventure make learning fun.  Moreover, there is no arrogance in his books.  The words “so far,” “unknown,” and “as yet” are sprinkled throughout the text.  He is not afraid to admit when science (or, indeed, when he himself!) has been mistaken, when theories are disproven, educational assumptions found incorrect. He writes with the understanding that our scientific knowledge–like life itself–is still evolving. And like so much of his writing, it only serves to prompt the reader into thoughtful reverie: where might science take us in the future? What will be revealed years, decades, centuries from now, and how will this impact the world?  The creative and wondrous question “What if?” floats like a butterfly through its chapters.

Dr. Martin describes how these seemingly abandoned alligator dens may have indeed been dug when water was present, but that even despite drought, parts of their internal structures may connect with the groundwater table.  Water within the den may have also attracted thirsty birds and animals on the island.  He and his students later found the ravaged corpses and bones from such unsuspecting creatures both in and outside of other forest dens.

“All of this trace evidence told us the alligators could switch from aquatic to terrestrial predation if necessary, like a shark deciding it was going to turn into a lion.  This surprising behavioral transformation and adaptability in alligators was made possible through their dens, which during times of environmental change became all-purpose hunting lodges.” – page 7, “The Evolution Underground: Burrows, Bunkers, and the Marvelous Subterranean World Beneath Our Feet,” by Dr. Anthony J. Martin, Pegasus Books

And thus begins his exploration of the animals—including humans!—worms, insects and birds that have created sanctuaries below ground.  Burrows, he posits, have made survival possible throughout Earth’s history, and these underground homes have made and continue to make enormous impact on life above ground.

“The bigger picture behind these everyday observations of many holes in the ground, however, is that the long history of these burrowing invertebrates completely altered global environments, from the deepest sea to the highest mountains, and even affected the atmosphere and climate.  In short, the entire surface of our planet is built upon one big complex and constantly evolving burrow system, controlling the nature of our existence.” – page 14, “The Evolution Underground: Burrows, Bunkers, and the Marvelous Subterranean World Beneath Our Feet,” by Dr. Anthony J. Martin, Pegasus Books

Dr. Martin encourages us to take a closer look at a generally overlooked part of our world. That closer look involves fascinating details about creatures and places one may not have realized existed.  Burrowing owls–with their photogenic and often amusing images–may be familiar, but perhaps not so much the charming fairy penguins of Tasmania, or the alarming assassin flies associated with gopher tortoise burrows, who both kill and start digesting their hapless victims with an injection of neurotoxins and enzymes.

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Image of burrowing fairy penguins, courtesy of Getty Images
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Slideshow of burrowing owls, courtesy of Getty Images

 

Perhaps the most powerful section of the book—one that really drives home his point about survival underground—involves the eruption of Mount St. Helens in Washington State thirty-seven years ago.

Whether you’ve only read about it or whether you’ve actually visited, Mount St. Helens is a stark reminder of how devastating Nature can be.  After a couple of months of earthquakes, the volcano erupted in the morning of May 18th, 1980. Not only did it obliterate everything in its path, the eruption and its aftermath killed 57 people and all of the wildlife within about 150 square miles.

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Image of Mount St. Helens before the eruption of 1980, photo by Jeff Goulden, courtesy of Getty Images

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Image of Mount St. Helens today, courtesy of Getty Images

Here, Dr. Martin uses creative nonfiction (or ‘narrative nonfiction’) to help illustrate how, despite this traumatic event, the entire area made a comeback.  Loowit, a sweet little fictional pocket gopher, takes the reader through some of the natural events that transformed devastation into renewal and rebirth.

He describes her home: a branching set of underground tunnels and rooms that can reach up to 500 feet long, complete with food storage areas, latrines, and other chambers. Although undeterred by snow, she was, at the time of the eruption, comfortably ensconced in her burrow.  This saved her.  He takes us through how she emerges after the eruption, her confusion, her tentative steps back into a new world above ground, how she and other survivors may have eventually formed communities.

In sum, in a world that now knew mostly death and destruction, these pocket gophers not only survived, but kept surviving, and in so doing, helped bring life back to an area that did not outwardly appear to contain much.

…these little ecosystem engineers began terraforming the previously desolate landscape, first by helping plants take root and grow. Each individual pocket gopher was capable of overturning more than a ton of soil each year…” – page 262, “The Evolution Underground: Burrows, Bunkers, and the Marvelous Subterranean World Beneath Our Feet,” by Dr. Anthony J. Martin, Pegasus Books
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Image of a pocket gopher, courtesy of Getty Images

Of the 55 mammal species in the area of Mount St. Helens in May 1980, only 14 survived the volcanic eruption and its collateral damage. Surface-dwelling elk, deer, black bears…and all other large- to medium-size mammals perished. On the other hand, nearly all the small mammals that lived were burrowing rodents…One of the few non-rodent survivors was the tiny Trowbridge’s shrew (Sorex trowbridgii), which (not coincidentally) is also a burrower.  Pocket gophers are active year round, but many other small-mammal species were both underground and still hibernating when the eruption took place.  The fortuitous timing of this disaster at the transition between winter and spring thus greatly enhanced the chances of these minutest of mammals to emerge and thrive.  Of the rodents that had already come out of hibernation, nocturnal species were doubly lucky to have already retired for the day in their burrows when the blast occurred.  Had the volcano erupted at night, many more would have died.” – page 264, “The Evolution Underground: Burrows, Bunkers, and the Marvelous Subterranean World Beneath Our Feet,” by Dr. Anthony J. Martin, Pegasus Books

For the pocket gopher populations that survived the eruption of Mount St. Helens in 1980, their collective actions were the key to turning a desolate, monochromatic landscape back into a vibrant and verdant one.  From a geological perspective, their effects were astoundingly quick, with partial ecological restoration apparent within just five years of the eruption. Consequently, pocket gophers and other burrowing animals that lived beyond May 18, 1980, send a powerful message about the benefits of burrows for surviving such an ecologically traumatic events, as well as for their role in restoring an ecosystem after it is nearly destroyed.” – pages 266-267, “The Evolution Underground: Burrows, Bunkers, and the Marvelous Subterranean World Beneath Our Feet,” by Dr. Anthony J. Martin, Pegasus Books

 

I want more books like “The Evolution Underground” and “Dinosaurs Without Bones.”  Books that tickle my intellect and my sense of humor.  Books that pull me in with their interesting anecdotes, their engaging playfulness, their sensitivity to all genders (ie: not referring to all humans as “mankind” or simply “man”), and their ability to make me think outside the pages.

When I read a book and am left not only with the satisfaction that comes from something that I’ve enjoyed but also an eagerness for more, I know I’ve found a talented author.

Dr. Anthony Martin is, indeed, a talented author.

 

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A sincere and enthusiastic THANK YOU to Dr. Anthony Martin for his willingness to connect by phone and for his generous responses to my questions!  It was a pleasure and an honor to be able to speak with him, and—like his writing—he made it fun!  I eagerly (if impatiently) await any possible future work.  

FULL DISCLOSURE: The author of this blog loved Dr. Martin’s previous book with Pegasus, “Dinosaurs Without Bones,” and thus, jumped at the chance to review his latest work (fully predisposed to embrace it) by requesting a review copy from the publisher.  I am very grateful to Pegasus Books for the opportunity to do so. I am specifically grateful to Deputy Publisher, Jessica Case, with whom it was wonderful to work!

Dinosaurs Without Bones

Fossilized Footprints – Dr. Karen Chin on the work of Dr. Martin Lockley

There is something uniquely spectacular about trace fossils.

Trace fossils—or ichnofossils—are fossilized remnants of animal activity. They are echoes of animal life, many that are millions of years old, that we can see and touch, tantalizing clues into their behavior and environment.

These traces take a number of forms, including coprolites (feces), gastroliths (stones ingested to help digestion), burrows, nests, and footprints.

 

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[image of dinosaur tracks, Colorado, courtesy of David Parsons and Getty Images]

Footprints are the focus of Dr. Martin Lockley’s work.  Over 30 years of his fossilized track research now resides at the University of Colorado Boulder.

Dr. Karen Chin, another trace fossil specialist with decades of experience, is widely known for her work on coprolites.

Coprolite - Dr. Chin MOS

 

MOS - Dr. Karen Chin coprolite

 

[images of coprolite and display info from the Boston Museum of Science, taken by the author]

The work of these two scientists comes together in the exhibit “Steps in Stone,” now at the University of Colorado Museum of Natural History.  Showcasing some of Dr. Lockley’s extensive collection, the exhibit is curated by Dr. Chin.

Steps in Stone entrance

[image of exhibit entrance, courtesy of the CU Museum of Natural History]

Originally from the UK, Dr. Martin Lockley began teaching at the University of Colorado Denver in the 1980’s.  He retired in 2010, but his research continues today.

“When he decided to retire from his professor position,” Dr. Chin explained in a phone interview, “he wanted his research collection to go to a place where it would be cared for in perpetuity and would still be available for people to study.  And since the University of Colorado Boulder is a sister institution to the University of Colorado Denver, it made sense for the collection to come to us.”

An accompanying website, with text written by Allison Vitkus—one of Dr. Chin’s graduate students—Dr. Karen Chin and Dr. Martin Lockley, describes in more detail the type of tracks Dr. Lockley has collected and donated to the University.

“Because of Prof. Lockley’s efforts, the University of Colorado’s Fossil Tracks Collection is exceptional in having specimens that represent tremendous temporal, taxonomic, and geographic breadth. It includes around 3,000 original or replica specimens of footprints and trackways, as well as about 1,600 full-size acetate footprint and trackway tracings. These specimens come from over 20 countries on five continents (including 21 states within the USA).” – Allison Vitkus, Dr. Karen Chin

http://www.ucmp.berkeley.edu/science/trackways/index.php

Moving such a collection from one university to another is not a small enterprise.

“Martin Lockley and I applied for and received an NSF (National Science Foundation) grant to help us transfer the tracks to our museum.”

Dr. Chin described the process of creating the current exhibit, a team effort of about 15 people from various departments within the Museum of Natural History.

“Allison and I had already been writing about different aspects of fossil track research.  We sat down and asked, ‘what are the things that we think are the most fundamental and interesting concepts of fossil tracks that would be interesting for people to learn about?’  We then put together a list of things we wanted to write about and matched that with tracks in the collection.”

Dr. Karen Chin and docents

 

[image of Dr. Karen Chin and exhibit docents, courtesy of the CU Museum of Natural History]

“We decided we wanted people to think about the concept of ‘moving’ and to recognize that fossil tracks tell us about locomotion in the past. ”

In other words, it is not just a look backward in time; it encourages the visitor to think about movement in all forms today and the evolution of that movement over Earth’s history.

Consider, for example, how fish might make tracks: fins brush the ground while swimming in shallow water.  Consider, too, the tracks animals make while running, walking, limping, or even swimming.   The type of footprint remaining and the length between each step (or stroke) offers valuable insight to scientists. Insects, mammals, birds, pterosaurs, dinosaurs….all of these species have left their marks in stone, and all of them are represented in this exhibit.

To help highlight how different body structures affect the type of tracks an animal leaves, members of the museum’s educational department procured imitation animal tails that kids can wear.  Kids are also encouraged to ‘Walk Like a Pterosaur!’ in which they can don representations of pterosaur forelimbs with wings.

“There’s a portion of the exhibit that’s called ‘Locomotion Without Legs,’ that reminds us that not all animals that leave tracks or traces have legs,” said Dr. Chin. “Modern snails and sea urchins and are good examples of this.”

“We discuss the oldest evidence that we know of for movement in the fossil record, which is about 565 million years. We don’t know what kind of animal made the trace. It may have been something like a sea urchin, but we just don’t know.”

“There are a certain number of deposits around the world that preserve weird impressions of animals from before the Cambrian,” she continued. “Actually, we don’t even know whether all of them were animals or plants! There are no modern analogues of these organisms because they went extinct.”

“One of the oldest deposits of this particular biota comes from Newfoundland.  Researchers found an unusual trace in this deposits that extends for several inches.  The trace appears to provide evidence of locomotion.  This suggests that an animal had the capacity to move itself, which further suggests that it had muscles.  This is a huge deal because the fossil trace is so old. I think this is very cool because we often take our ability to move for granted.”

This particular trace fossil was described by Dr. Alexander Liu, Dr. Duncan McIlroy, and Dr. Martin Brasier in 2010.  How fascinating to think that something this small and from an organism that remains a mystery provides important evidence for movement when the Earth was still relatively young. (First evidence for locomotion in the Ediacaran biota from the 565 Ma Mistaken Point Formation, Newfoundland) The actual trace fossil is not part of the exhibit, but its image is available for visitors to see.

“We often automatically think that animals have the ability to move from point A to point B,” Dr. Chin mused. “But there are a number of very successful animals that live without relocating from one place to another, such as sponges and corals.   So it is interesting to think about when animals first developed the ability to move. ”

Another example of the variety and importance of tracks are the Laetoli trackway: a set of prints from Tanzania.  The exhibit displays a life-sized cast of the trackway, footprints from two hominin adults and a smaller set of footprints that might have been a child.

“Their footprints were preserved when they walked on recently deposited volcanic ash. These tracks are important because they provide some of the earliest evidence that our ancient relatives, the australopithecines, walked bipedally.”

“As Dr. Lockley has continued his research on tracks,” explained Dr. Chin, “he has often acquired replicas of fossil tracks from around the world.  That is what is great about tracks: that you can make a lot of different casts of them.”

“It’s an intense process,” Dr. Chin stated, referring to the creation of an exhibit. “There are so many details. But I gained new appreciation for the great work that the exhibit designers and the museum education people do.”

In response to whether it was a positive experience, she said, “I did enjoy it!”

“Now, I have to say,” she laughed, “it’s a lot of work.  I didn’t mind the work, it’s just that I’m also teaching and doing research, so it’s kind of hard to juggle doing all of that at the same time.”

“I think there are two larger points that I’d like people to take away from the exhibit.

“I want people to gain a sense of appreciation for the tremendous amount of research Dr. Lockley has done on fossil tracks all over the world.

“I also want people to appreciate the informative value of tracks and other trace fossils.”

Dr. Karen Chin and docents 2

[image of Dr. Karen Chin and docents, courtesy of the CU Museum of Natural History]

“At many times we tend to focus on body fossils: the bones of mammoths and the bones of dinosaurs, for example. They are very interesting, and they really fire up our imagination in considering what those ancient animals were like.

“But, I also want people to appreciate that trace fossils–which provide evidence organisms’ activity—also offer important information on the history of life.

“It’s very much akin to walking on a trail these days and looking for animal sign.  You look for tracks and scat and scratches and toothmarks.  And we do the same when we look for trace fossils in the fossil record.  Tracks are just one exciting example of trace fossils.”

 

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A Mammuthus columbi-sized THANK YOU to Dr. Karen Chin for her time, her fascinating insight and for generously helping me understand Ediacaran biota!  It was a tremendous honor and pleasure for me to connect with her.  An enormous thank you to Cathy Regan as well for providing wonderful images of the exhibit!

Steps in Stone” is available through December 31, 2015: http://cumuseum.colorado.edu

If you are interested in learning more about trace fossils, Dr. Martin Lockley has written a number of books.  Dinosaurs Without Bones by Dr. Anthony J. Martin was published this year, and this author highly recommends it!