NASA Image of the Day

October 30, 2018 Leave a comment

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NASA Image of the Day

October 7, 2018 Leave a comment

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Book Review – The Tyrannosaur Chronicles: The Biology of the Tyrant Dinosaurs

June 15, 2018 Leave a comment

Hone bookTyrannosaurus rex looms large in our imagination, reigning (according to paleontologist Robert T. Bakker) as possibly “the most popular dinosaur among people of all ages, all cultures, and all nationalities.”

The Cretaceous period monster, popularized in print, on the big screen, and on television for a hundred years, got its name when its discoverer decided it likely resembled a giant lizard-like creature.  Over time commentators and popularizers have helped to grow a perception that these animals were perhaps the most fearsome predators ever to walk the planet.

Paleontologist David Hone has spent much of his professional life working to understand T. rex and its close relatives. From his research home at Queen Mary University of London, Hone has focused heavily on both the dinosaurs (generally predatory) called theropods and the flying reptiles called pterosaurs that were also common during the Mesozoic era.

His recent book, The Tyrannosaur Chronicles: The Biology of the Tyrant Dinosaurs, is not only a worthy guide to the history of our fascination with the beast. Hone also brilliantly and insightfully explains what we really know about the family of theropod dinosaurs popularly known as tyrannosaurs.

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“Sue,” the largest-known fossil specimen of a Tyrannosaurus rex, is in Chicago’s Field Museum of Natural History. Image courtesy Connie Ma/Wikimedia Commons.

The book begins with a look at some basics of anatomy. This is useful because, to anyone seeking to understand how dinosaur species related to each other, how their skeletal structures likely worked, and even how they may have behaved, insight begins with the bones.

Hone then summarizes the history of dinosaur discovery.  He pays particular attention to the 19th century work of Joseph Leidy, Colorado educator Arthur Lakes, and the famed fossil hunters Edward Cope, Joseph Tyrrell, and Barnum Brown. Each of these early paleontologists contributed significantly to the eventual identification of the “tyrant lizard king” (as the name Tyrannosaurus rex means).

One of the most helpful parts of these sections of the book, aside from the valuable background they provide, is Hone’s skillful recounting of their context. Describing, for example, one of the key conclusions of the current “dinosaur renaissance” – namely, that modern-day birds are descendants of the dinosaurs – Hone helps the reader understand clearly why scientists believe this deduction makes sense:

“If dinosaurs were the ancestors of birds, and non-avian dinosaurs had a number of bird features, then some of the characteristics we traditionally ascribe to birds could, even should, be present in the Mesozoic. Dinosaurs didn’t have to be just reptile-like; they could have been bird-like in some, indeed many, regards.”

Hone goes on to help the reader, whom he wisely seems to assume is generally unfamilar with the particulars of zoology, understand where dinosaurs sit in the category of animals called reptiles. Hone also takes care to explain how tyrannosaurs fit into that widely beloved group of dominant creatures that ruled Earth for so long.

Yutyrannus

This artist’s conception of Yutyrannus huali, discovered in China in 2012, is by Brian Choo. Courtesy Nature Publishing Group.

From there, Hone provides a brief look at the 29 known species of tyrannosaurs. Beyond T. rex, these include some fascinating animals. One species in the family, called Yutyrannus hauli, was probably completely feathered. Another, known as Daspletosaurus hornei, may have had an extremely sensitive, scale-covered face that could possibly have helped it to detect the temperature of eggs in a nest. There’s even a glance here at the controversy involving the small tyrannosaur thought by some scientists to be an entirely different species from T. rex called Nanotyrannus and by others to be simply a juvenile T. rex.

Hone displayes a careful and picturesque command of words when he describes the internal anatomy of a tyrannosaur. He is also funny at times. For example, when explaining how a male tyrannosaur may have mated with its female counterpart with a structure called an intromittent organ, the author refers the reader to ducks. Yes, ducks.

Naturally, Hone explores tyrannosaur jaws, stomachs, digestion, locomotion, and limbs, too, among other treats of dino biology. Nor does he overlook the recent evidence that these animals, or at least some of them, were feathered.

 “Feathers are rarely preserved as the conditions for their preservation have to be near perfect, and we have to be lukcy enough to find fossils of feathered specimens. Thus even though only two tyrannosaurs are directly known to have had feathers, it is reasonable to infer that all of them did.”

The writer also discusses the question whether tyrannosaurs were warm-blooded. It would not be sporting to give away the destination to which the reader is led by the rather beautiful narrative Hone provides. Instead, it might be best to simply say that he introduces readers to a concept that might cause them to raise their eyebrows in surprise and even excitement about the way the huge predators, and maybe other dinosaurs, could have regulated their body temperature.

The second half of the book scrutinizes a number of other captivating questions about tyrannosaurs, including how they found their food (was the mighty T. rex a mere scavenger?), what they probably ate, and whether they may have been social animals.

Among the only flaws in the book are these: first, although the illustrations by Scott Hartman are illuminating, there are too few of them. Second, Hone displays a notable fondness for the word “rather.” It appears enough times in the text that the reader loses count. These minor glitches do not detract from the book’s excellence.

There are other excellent books about dinosaurs – too many, in fact, to list here – and Hone’s seems destined to take its place among them. For all who love the prehistoric leviathans (and smaller dinos, too), this spectacular survey of T. rex and its cousins should be high on the reading list.

Hone, David. The Tyrannosaur Chronicles: The Biology of the Tyrant Dinosaurs. New York: Bloomsbury-Sigma. Reprint edition, 2017. ISBN 1472911288.

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This 2008 German postage stamp, though not totally accurate in its depiction of Tyrannosaurus rex anatomy, shows the dinosaur in a manner that is likely familiar to many. Image courtesy Deutsche Post AG/Wikimedia Commons.

New Horizons probe sends home images from greatest ever distance

February 10, 2018 Leave a comment

 

Kuiper Belt objects - New Horizons, Dec. 2017

These false-color images, obtained by New Horizons in December 2017, show two Kuiper Belt Objects: 2012 HZ84 (left) and 2012 HE85. These photographs are the most distant ever obtained by a spacecraft. They are also the closest any camera has ever come to celestial objects in the Kuiper Belt. Image courtesy NASA, Johns Hopkins University Applied Physics Laboratory, and Southwest Research Institute.

NASA’s New Horizons probe, which electrified astronomers and other space enthusiasts with its 2015 fly-by of dwarf planet Pluto, has now set a record for the most distant photographs ever obtained by a human spacecraft.

On Dec. 5 the probe snapped an image of the Wishing Well galactic open star cluster. New Horizons was then 6.12 billion kilometers from Earth.

That beat the previous photography transmission record set in 1990 by Voyager 1 when it was about 6.06 billion kilometers from our home planet.

But the little probe that can was not yet finished.

Two hours after sending home the Wishing Well imagery, New Horizons obtained and transmitted photographs of Kuiper Belt objects 2012 HZ84 and 2012 HE85.

All of the December 2017 photographs were captured via the Long-Range Reconnaissance Imager, an 8.8 kilogram-sized digital camera-type device equipped with a telescope lens and reinforced to function in the cold of space.

New Horizons visited Pluto in 2015. During that historic rendezvous, the spacecraft approached to within 13,000 kilometers of the dwarf planet.

The probe has been in hibernation mode since Dec. 21, 2017.

 

NASA Image of the Day: The Rockies from Space

January 10, 2017 Leave a comment
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North America’s Rocky Mountains are seen in this image captured by an astronaut aboard the International Space Station, Jan. 9, 2017. Image courtesy European Space Agency, NASA.

NASA’s Image of the Day for Jan. 10, 2017 is a doozy.

Astronaut Thomas Pesquet of the European Space Agency snapped a photo of North America’s Rocky Mountains from the International Space Station.

When Pesquet shared the photograph on social media, he wrote that “the Rocky mountains are a step too high – even for the clouds to cross.”

 

Wind topples California’s famous Tunnel Tree

January 9, 2017 Leave a comment
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This photo of California’s Pioneer’s Cabin Tree, dated 1866, is from the Library of Congress.

The Pioneer Cabin Tree, a California landmark loved by tourists for decades, has been toppled by wind.

A giant sequoia, the huge tree was 150 feet tall. The cutout in its trunk was wide enough to drive cars through and, over the years, many cars did pass under the tree.

Eventually California authorities closed access to cars, but in recent years there has been a hiking trail that leads to it and visitors could still stand in the cutout.

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This photo of the base of California’s Tunnel Tree was posted on the Facebook page of the Calaveras Big Trees Association. Image by Claudia Beymer.

Located in Calaveras Big Trees State Park, the Pioneer Cabin Tree – also known as the Tunnel Tree – was estimated to be over 1,000 years old. The large hole in its trunk was carved by owners of the land on which it grew in 1880.

A report in the San Francisco Chronicle explained that there is no way to be sure of the reason why the Tunnel Tree could not withstand the storm that has hit the Golden State in recent days. That storm, the worst in at least a decade, flooded Calaveras Big Trees State Park. The Chronicle explained that the Tunnel Tree’s shallow root system, typical for a sequoia, was likely a factor.

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This photo shows the splintered remains of California’s Tunnel Tree on Jan. 8, 2017. Image courtesy Calaveras Big Trees Association, photo by Jim Allday.

Giant sequoias (Sequoiadendron giganteum), also known as redwoods, are the world’s largest organisms by volume. They can grow to a height of 85 meters and have been known to live for more than 3,500 years.

Now that the Pioneer Cabin Tree has fallen, there are no longer any known living sequoia trees with tunnels through their trunks.

New book by paleontologists Naish and Barrett is a treat for dinosaur fans

December 19, 2016 Leave a comment

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Those of us who love dinosaurs know that there is something poetic about these animals – the spectacular size of some,  their amazing variety, the mysteries of their long life on this planet . We still feel a thrill when we envision the fantastic beasts and we sometimes find ourselves drifting into a reverie in which we imagine the world under their 140 million-year domination. We can almost see, in our mind’s eye, the graceful long-necked sauropods nibbling the trees and shrubs, the stalking bipedal, sharp-toothed theropods tall and small, and the horned, crested, and armored herbivores wandering the landscape.

Our endless willingness to imagine the great beasts, and our persistent desire to learn more about them, is catered to by a growing variety of mass market books that aim to help us understand their biology and the ecosystems in which they lived. One of the best recent additions to this library, by the British paleontologists Darren Naish (author of the popular Tetrapod Zoology blog) and Paul Barrett (of London’s Natural History Museum), stands out for its depth and its wide-ranging look at dinosaurs’ anatomy, behavior, diversity, and evolution.

The book, Dinosaurs: How They Lived and Evolved, starts with a look at some basic biological principles and the history of dinosaur discoveries. Readers are provided a cogent overview of Earth’s geology and climate during the Mesozoic era, the value of cladistics as a tool to make sense of dinosaur variety, and the place of dinosaurs in the larger group of animals known as archosaurs.

Naish and Barrett then move on to a helpful explanation of the relationships among dinosaur species and a detailed look at dinosaur skeletal systems.

This discussion shines for its skillful and picturesque descriptions of the major dinosaur groups. The authors focus not just on the famous Saurischians and Ornithiscians; they take the reader into a just-deep-enough examination of the clades into which these groups are divided.

In the third section of the book Naish and Barrett shift to an examination of scientists’ current understanding of the deeper aspects of dinosaur biology: their diets, their mating habits, the intricacies of their movement, and their social behaviors. This part of the book is a smorgasbord of insights into how fossils, both trace and body, teach us about the structure of an animal’s life.

Next we are presented with a thorough discussion of modern dinosaurs. Here Naish and Barrett not only delve into the ways in which avian anatomy resembles that of their coelurosaur cousins, but also explain the current understanding of feather origins and the genesis of flight.

In the book’s final section Naish and Barrett, after a review of the impact by an asteroid or comet and its consequences for dinosaurs and their world, highlight another possible contributor to the Mesozoic terminus: active volcanoes around the planet.

The authors explain that, notwithstanding the ecological catastrophe that essentially ended their long reign over the planet’s biosphere (an incident known as the K-Pg event), dinosaurs may have been experiencing both climate change and a loss of diversity at the time it occurred. They take pains to emphasize that, contrary to popular myth, some dinosaurs did survive the end of the Cretaceous period. We know them, of course, as the birds.

Gracing the text are numerous photographs, graphs, and computer-generated reconstructions. Naish and Barrett did not, though, include citations to scientific papers or a bibliography.

Dinosaurs: How They Lived and Evolved is ideal for readers that have some basic familiarity with the biological sciences, though detailed knowledge is not required to enjoy the book.

Published by Smithsonian Books and carrying a cover price of $29.95, the book is a worthy and entertaining read for all of us who continue to be fascinated by the dinosaurs.

NOTE: This reviewer obtained a copy of Dinosaurs: How They Lived and Evolved on loan from the Arapahoe Library District. He was not asked by any publisher or author to prepare this review and has not been compensated for it.

Lisa Rayner's Food & Garden Blog

I am a do-it-yourselfer. I have written how-to books on sustainable permaculture gardening, natural home canning, baking sourdough bread and solar cooking.

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