Follow Mark Norell, Chair and Curator-in-Charge of Paleontology at AMNH, as he gives an insightful tour of Silk Road, traveling from Xi’an, the capital of China’s Tang Dynasty; Turfan, a verdant oasis and trading outpost; Samarkand, a center for prosperous merchants who thrived on the caravan trade; and Baghdad, a cosmopolitan hub of commerce and scholarship that flourished as a leading intellectual center of the time.
Mark Norell, Chair of the Division of Paleontology at the American Museum of Natural History, has published a new paper revealing the Archaeopteryx, once thought to be the first bird, was in fact a feathered dinosaur.
First found in Germany in the 1860’s and dating to 150 million years ago, Archaeopteryx has long been considered the iconic first bird. But microscopic imaging of bone structure published in PLoS One shows that this famously feathered fossil grew much slower than living birds and more like non-avian dinosaurs.
“For a long time, Archaeopteryx was considered the archetypical bird primarily because it had feathers, although it retained typical dinosaur features like a long tail and teeth,” said Norell. “But the discovery of classical bird features like feathers and wishbones have recently been found in many non-avian dinosaurs blurring the line of what constitutes a bird.”
De-Leeching Ankles on a Desolate Coast with Mark Siddall, Curator of Invertebrate Zoology
This year, scientists at the American Museum of Natural History are celebrating the 200th anniversary of Charles Darwin’s birth and the 1859 publication of On the Origin of Species with a collection of vignettes describing expeditions and ideas with links to Darwin’s seminal work.
The Island of Chiloé may protect part of the Chilean coast from the winds of the Pacific Ocean, but it offers little refuge for the travelling naturalist.
When Charles Darwin rode with his team across the island on January 22, 1835 he recalled a beautiful day and “trees…in full flower [that] perfumed the air.” Yet even this lovely vista “could hardly dissipate the effects of the gloomy dampness of the forest. Moreover, the many dead trunks that stand like skeletons never fail to give to these primeval woods a character of solemnity.”
More than 160 years later, Mark Siddall and his graduate student Liz Borda made a similar excursion to what is now the Parque Nacional de Chiloé. As they tramped through dense stands of old-growth Nothofagus and Fitzroya trees in intense wind and
driving rain, they found they shared Darwin’s observation that if they “could forget the gloom and ceaseless rain of winter, Chiloé might pass for a charming island.”
The project that brought Siddall and Borda to Chile shared something else with Darwin, too. “Our purpose in Southern Chile was to rediscover two species of leeches, Americobdella valdiviana and Mesobdella gemmata, that I thought were critical to understanding the evolution of this group,” says Siddall. “Transitional forms—species that have characteristics of two distinct but evolutionarily related groups—are central to Darwin’s theories.”
