Question 1

How do you say Maastrichtian?

Accepted Answer

Maastrichtian is pronounced maas-TRIK-tee-un. The stress falls on the second syllable, TRIK. The double-a in Maas gives it a broad open vowel at the start, and the ending is a soft 'tee-un' sound. Say it slowly: MAAS, then TRIK, then tee-un, and you've got it.

Question 2

What does Maastrichtian mean?

Accepted Answer

Maastrichtian simply means 'belonging to Maastricht', a city in the Netherlands. Geologists name time periods after the locations where the defining rock layers were first studied. The distinctive limestone and chalk deposits around Maastricht were laid down during this exact interval of geological time, so the period was named in the city's honor by Belgian geologist André Hubert Dumont in 1849.

Question 3

When did the Maastrichtian period start and end?

Accepted Answer

The Maastrichtian lasted from approximately 72.2 million years ago to 66 million years ago, a span of about 6.2 million years. It was the final age of the Cretaceous Period and the last chapter of the Mesozoic Era. It ended with the Chicxulub asteroid impact that caused the mass extinction wiping out the non-avian dinosaurs.

Question 4

Did T. rex live in the Maastrichtian?

Accepted Answer

Yes, Tyrannosaurus rex is a Maastrichtian dinosaur. T. rex lived during the last roughly 2 to 3 million years of the Maastrichtian, appearing in the fossil record around 68 million years ago. It was one of the very last non-avian dinosaurs to exist before the K-Pg mass extinction ended the period 66 million years ago.

Question 5

What caused the end of the Maastrichtian?

Accepted Answer

The Maastrichtian ended when a massive asteroid approximately 6 miles wide slammed into present-day Mexico 66 million years ago, creating the Chicxulub crater. The impact caused catastrophic wildfires, blocked sunlight for years with debris and soot, triggered acid rain, and collapsed food chains globally. This event, called the K-Pg mass extinction, killed roughly 75% of all species on Earth including all non-avian dinosaurs.

Question 6

What dinosaurs lived during the Maastrichtian?

Accepted Answer

Some of the most famous dinosaurs of all time lived during the Maastrichtian. These include Tyrannosaurus rex, Triceratops, Ankylosaurus, and Edmontosaurus in western North America. Other regions had their own distinct dinosaur faunas, including titanosaur sauropods in South America, abelisaurid predators in Europe and India, and hadrosaurs on multiple continents. The Maastrichtian had some of the highest dinosaur diversity of the entire Mesozoic Era.

Question 7

What came before the Maastrichtian?

Accepted Answer

The Maastrichtian was preceded by the Campanian Age, which lasted from approximately 83.6 to 72.2 million years ago. The Campanian was also part of the Late Cretaceous and was itself a time of tremendous dinosaur diversity. Many of the same animal groups present in the Campanian, such as ceratopsians, hadrosaurs, and tyrannosaurs, continued evolving into the Maastrichtian.

Question 8

What came after the Maastrichtian?

Accepted Answer

The Maastrichtian was followed by the Danian Age, which is the first age of the Paleogene Period and the Cenozoic Era. The Danian began 66 million years ago immediately after the K-Pg mass extinction. It was a time of recovery and reorganization, when mammals, birds, and other surviving groups began diversifying rapidly to fill the ecological roles left vacant by the extinct dinosaurs.

Question 9

Where is Maastricht and why is it important for dinosaur science?

Accepted Answer

Maastricht is a city in the southern Netherlands, near the borders of Belgium and Germany. It sits on the River Meuse and is the capital of the Limburg province. The limestone quarries in and around Maastricht have been famous since the 18th century for their extraordinary fossils, including the discovery of Mosasaurus in the 1760s to 1770s, one of the first giant prehistoric creatures to be seriously studied by European scientists.

Question 10

Is the Maastrichtian the same as the Late Cretaceous?

Accepted Answer

Not exactly. The Late Cretaceous is a much longer span of time that includes several ages or stages. The Maastrichtian is specifically the final and youngest age within the Late Cretaceous, lasting from 72.2 to 66 million years ago. Think of the Late Cretaceous as a whole book and the Maastrichtian as its final chapter.

Question 11

How warm was it during the Maastrichtian?

Accepted Answer

The Maastrichtian was significantly warmer than today, with global average temperatures estimated at roughly 4 to 10 degrees Celsius higher than modern averages. There were no permanent polar ice caps, and even Arctic and Antarctic regions supported forests and wildlife. This warmth was driven by higher concentrations of carbon dioxide in the atmosphere and different ocean circulation patterns compared to today.

Question 12

Were there oceans during the Maastrichtian?

Accepted Answer

Yes, and some of them were in very unexpected places. During the Maastrichtian, sea levels were dramatically higher than today, and a massive shallow inland sea called the Western Interior Seaway flooded through the center of North America, splitting the continent in two from the Arctic to the Gulf of Mexico. This seaway teemed with mosasaurs, plesiosaurs, large fish, and vast numbers of ammonites.

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