The evolution from dinosaurs to birds included significant anatomical modifications. One crucial change was the development of a tiny wrist bone called the pisiform that helped stabilize wings in flight. A new study suggests that this bone appeared in bird ancestors millions of years earlier than first thought.

Paleontologists at Yale and Stony Brook University led a research team that made the discovery after examining fossils from two species of bird-like dinosaurs found in the Gobi Desert in Mongolia. The findings were published in the journal Nature.

“We were fortunate to have two immaculately preserved theropod wrists for this,” said Alex Ruebenstahl, a student at Yale’s Graduate School of Arts and Sciences. Both Ruebenstahl and his colleague Bhart-Anjan Bhullar noticed that the wrist bones were small and had shifted during decay and preservation.

The evolution of theropod dinosaurs into birds included significant anatomical modifications, such as changes in the pelvis and its surrounding musculature – and a transformation of the dinosaur forelimbs. One key change was the replacement of the ulnare with the pisiform bone in birds. In living birds, the pisiform is an unusual wrist bone that forms within a muscle tendon.

“This integration is particularly important for stabilizing the wing during flight,” said Bhullar. The discovery suggests that the integrated pisiform evolved prior to modern avian flight, and was diminutive in these near-bird dinosaurs, which is consistent with their limited flight capabilities.

The research continues a rich Yale tradition of advancing understanding of bird evolution from dinosaurs. In the 1960s, Yale paleontologist John Ostrom identified another wrist bone found in both meat-eating dinosaurs and modern birds. In the 1980s, Yale paleontologist Jacques Gauthier definitively showed that this wrist bone linked dinosaurs to birds.

The study’s lead author, James Napoli, of Stony Brook University, collaborated with Ruebenstahl and Bhullar to re-identify wrist bones in other dinosaurs as pisiforms. Further analysis showed the unidentified bones were indeed pisiform bones. The researchers then expanded their efforts to study the development of some of the flight muscles associated with the pisiform.

The research was conducted by a team including co-authors Matteo Fabbri, Jimgmai O’Connor, and Mark Norell, and furthered understanding of bird evolution from dinosaurs.

In this groundbreaking study, two scholars from Girton College, Cambridge, present their findings on the Humiliamini sermon, which contains the enigmatic reference to Wade. By analyzing the writing style and arguments presented in the sermon, they conclude that it was likely written by Alexander Neckam or an acolyte familiar with his work.

The sermon’s focus on humility as a lesson in the face of human vices is strikingly relevant today. The researchers highlight the use of vivid animal imagery to convey these themes, including powerful men becoming like wolves and cunning individuals imitating serpents.

Their study sheds new light on the Song of Wade, a medieval literary mystery that has puzzled scholars for over a century. By uncovering its true meaning, this research contributes significantly to our understanding of medieval literature, history, and theology.

As one scholar notes, “This sermon still resonates today… It warns that it’s us, humans, who pose the biggest threat, not monsters.” The retranslation of the Song of Wade offers a powerful reminder of the importance of humility in our daily lives.

The Ancient Roots of Disease: Scientists Uncover 214 Prehistoric Pathogens in Human DNA

A groundbreaking study published in Nature has revealed that prehistoric humans were plagued by a staggering 214 ancient pathogens, dating back as far as 6,500 years ago. The research team, led by Professor Eske Willerslev from the University of Copenhagen and the University of Cambridge, analyzed DNA from over 1,300 prehistoric individuals, including those up to 37,000 years old.

This extensive study is the largest to date on the history of infectious diseases and sheds new light on the development of diseases caused by bacteria, viruses, and parasites. The findings suggest that humans’ close cohabitation with domesticated animals, particularly from the Pontic Steppe, played a significant role in the spread of these ancient pathogens.

One of the most striking discoveries is the presence of the plague bacterium Yersinia pestis, which was identified in a 5,500-year-old sample. This is the world’s oldest genetic trace of the disease that ravaged Europe during the Middle Ages, killing between one-quarter and one-half of the population.

The implications of this study are far-reaching and could have significant consequences for vaccine development and our understanding of how diseases arise and mutate over time.

Associate Professor Martin Sikora, the study’s first author, emphasized that “if we understand what happened in the past, it can help us prepare for the future, where many of the newly emerging infectious diseases are predicted to originate from animals.” This knowledge is crucial for developing effective vaccines and ensuring that current ones provide sufficient coverage or need to be updated due to mutations.

The study was made possible by funding from the Lundbeck Foundation. This research highlights the importance of understanding our shared history with ancient pathogens and serves as a reminder of the urgent need to develop targeted solutions for emerging infectious diseases.