The large-scale geological event known as the End-Cretaceous Mass Extinction had a profound influence on life on our planet. Three-quarters of all life on Earth perished during this time, from marine invertebrates like the ammonites, to the large avian and marine reptiles which had held their dominant place for so long, and of course the dinosaurs. In a geological instant, hundreds of non-avian dinosaur species, the product of more than 175,000,000 years of evolution, completely disappeared from the Earth.

The cause of this mass extinction event is an ongoing and often contentious debate in the scientific community. Did the extinction happen rapidly or was it the product of a long period of change in climate? Or perhaps the culmination of both factors?

One of the largest volcanic features on Earth, the Deccan Traps stretch across the Indian subcontinent, the remnants of these powerful flood basalts reaching depths of more than 1.2 miles (2,000m). The eruption of the Deccan Traps came in relatively fast pulses just before the recognized boundary between the Cretaceous and Paleogene Periods (c. 66.8 million years ago).

Sulphur-dioxide released by this eruption is thought to have cooled the planet by as much as 2°C (3.6°F), a data point which is reflected in the study of extinction rates in many smaller forms of life including foraminifera as well as larger species like the dinosaurs. The specimen in Age of Dinosaurs is a mixture of the portions of three distinct phases of the main eruption donated by Professor Gerta Keller of Princeton University. We are very grateful for Dr. Keller’s kind donation of this material which underlies a lifetime of work on this fascinating subject.

By contrast, the Chicxulub Asteroid Impact (c. 66 million years ago) provides a dramatic exclamation point to the end of the Mesozoic. At a minimum, the Chicxulub impactor was 6 miles (9.6km) in diameter, and the energy released likely exceeded more than 100 million megatons.

Evidence of massive fires and mega-tsunamis traced to this event have been found in many areas of the world, as well as a fine layer of the element Iridium which is known today as the K-Pg Boundary Layer. The discovery of this global layer and the eventual hypothesis is credited to Nobel Laureate Dr. Luis Alvarez and his son Dr. Walter Alvarez. The specimen in the Mini Museum is a mixture of the K-Pg Boundary Layer samples taken from across North America and Europe.

As pictured above, this item includes the physical evidence behind the two leading theories for the death of the dinosaurs: the Chicxulub Asteroid Impact and the flood basalts of the Indian Subcontinent known as the Deccan Traps.

The specimens are housed in an acrylic jar that is encased within a glass-topped riker display box. The box measures 4 1/2" x 3 1/2". A small information card is also included, which serves as the certificate of authenticity.

Please Note: the distribution of the material in each specimen will be unique. Product images are representative samples. The approximate size for each specimen is 2 cm wide by 1 cm tall (e.g. twice the size of the specimen in Age of Dinosaurs).

Few aspects of deep history fascinate humankind as much as the death of the dinosaurs. Even today, new revelations, such as Dr. Robert DePalma's discovery of mass kill sites that may literally capture the very day of the Chicxulub impact, can dominate world headlines for weeks. Exploration of these discoveries is also, in many ways, challenging moments for science.

The current mainstream explanation for the mass extinction of the non-avian dinosaurs derives from a theory proposed in 1980 by the Nobel Prize-winning physicist Dr. Luis Alvarez, his son geologist Dr. Walter Alvarez, and several others. It is by all accounts the leading theory, but when it was released in 1980 it dropped on the establishment like a... well, like an asteroid colliding with the Earth.

Inspired by the presence of iridium—a metal rare in Earth’s crust but common in meteorites and the deep innards of planets—in the “boundary clay” layers found worldwide at the K-Pg transition, the Alvarez hypothesis suggested the massive impact of an extraterrestrial body—a bolide, in other words, an asteroid or comet—triggered the dinosaur-destroying extinction.

In the 1990s, this theory was buoyed by the discovery of the nearly 200-mile-wide Chicxulub crater along the northern Yucatan coast of Mexico, which roughly matches the 66-million-years-ago timestamp of the K-Pg extinction event. In the decades since, numerous panels have reviewed calculations, samples, and methods and most have come to the conclusion that the Alvarez theory must be correct and exclusive.

Certainly, there is no doubt that a massive object collided with the Earth at the end of the Cretaceous. The latest research on the Chicxulub also suggests that the location of the primary impact was especially devastating. Sulfur aerosols released in mass quantities would make the atmosphere toxic and rapid ocean acidification due to increased carbon would mean death for marine species as well.

Yet if we've learned anything about life during the exploration of billions of years of history, it is that it is resilient in the face of overwhelming natural disasters. It really does find a way, at least in the short term. What truly impacts life on a grand scale is the march of time itself; the shifting of continents for example, and the large-scale effects of long-term climate change.

Not long before the Alvarez team presented their impact hypothesis in 1980, paleontologist Dewey McLean had suggested the end-Cretaceous mass extinction was caused by a series of enormous volcanic eruptions that built the flood-basalt province of the Indian subcontinent known as the Deccan Traps.

Though the Deccan Traps theory has been majorly overshadowed by the impact hypothesis essentially since the latter’s inception, it’s had a fierce proponent for decades in the form of the Princeton University Professor of Geosciences Dr. Gerta Keller.

Based on Dr. Keller's work with the unicellular marine organisms called foraminifera (or “forams,” for short)—which have left behind such an abundant and long-term fossil record that they’re something of a benchmark for tracking broader evolutionary trends—Keller contends the hundreds of thousands of years of Deccan Traps basalt floods were the primary driver of the K-Pg extinctions, not a bolide impact.