add major extinction events to calendar

1 files changed, 45 insertions, 2 deletions

diff --git a/CosmicCalendar.hs b/CosmicCalendar.hs
index d8f239b..5f5f3b3 100644
--- a/CosmicCalendar.hs
+++ b/CosmicCalendar.hs
@@ -464,12 +464,55 @@ Named Nyasasaurus parringtoni, the roughly 243-million-year-old fossils represen
     |]
     "",
 
+    CalendarEntry (445 & millionYearsAgo) Nothing
+    "The Ordovician Extinction"
+    "Fluctuating sea levels cause mass die-off of marine invertebrates"
+    [text|
+    The earliest known mass extinction, the Ordovician Extinction, took place at a time when most of the life on Earth lived in its seas. Its major casualties were marine invertebrates including brachiopods, trilobites, bivalves and corals; many species from each of these groups went extinct during this time. The cause of this extinction? It’s thought that the main catalyst was the movement of the supercontinent Gondwana into Earth’s southern hemisphere, which caused sea levels to rise and fall repeatedly over a period of millions of years, eliminating habitats and species. The onset of a late Ordovician ice age and changes in water chemistry may also have been factors in this extinction. 
+    |]
+    "https://www.amnh.org/shelf-life/six-extinctions",
+
+    CalendarEntry (370 & millionYearsAgo) Nothing
+    "Late Devonian Extinction"
+    "The Kellwasser Event and the Hangenberg Event combine to cause an enormous loss in biodiversity"
+    [text|
+    Given that it took place over a huge span of time—estimates range from 500,000 to 25 million years—it isn’t possible to point to a single cause for the Devonian extinction, though some suggest that the amazing spread of plant life on land during this time may have changed the environment in ways that made life harder, and eventually impossible, for the species that died out. 
+
+    The brunt of this extinction was borne by marine invertebrates. As in the Ordovician Extinction, many species of corals, trilobites, and brachiopods vanished. Corals in particular were so hard hit that they were nearly wiped out, and didn’t recover until the Mesozoic Era, nearly 120 million years later. Not all vertebrate species were spared, however; the early bony fishes known as placoderms met their end in this extinction.
+    |]
+    "https://www.amnh.org/shelf-life/six-extinctions",
+
+    CalendarEntry (445 & millionYearsAgo) Nothing
+    "The Great Dying"
+    "Mass extinction kills more than 95 percent of marine species and 70 percent of land-dwelling vertebrates"
+    [text|
+    So many species were wiped out by this mass extinction it took more than 10 million years to recover from the huge blow to global biodiversity. This extinction is thought to be the result of a gradual change in climate, followed by a sudden catastrophe. Causes including volcanic eruptions, asteroid impacts, and a sudden release of greenhouse gasses from the seafloor have been proposed, but the mechanism behind the Great Dying remains a mystery. 
+    |]
+    "https://www.amnh.org/shelf-life/six-extinctions",
+
+    CalendarEntry (201 & millionYearsAgo) Nothing
+    "Triassic-Jurassic Extinction"
+    "Death of more than a third of marine species and of most large amphibians"
+    [text|
+    This extinction occurred just a few millennia before the breakup of the supercontinent of Pangaea. While its causes are not definitively understood—researchers have suggested climate change, an asteroid impact, or a spate of enormous volcanic eruptions as possible culprits—its effects are indisputable. 
+
+More than a third of marine species vanished, as did most large amphibians of the time, as well as many species related to crocodiles and dinosaurs. 
+    |]
+    "https://www.amnh.org/shelf-life/six-extinctions",
+
     CalendarEntry (65 & millionYearsAgo) Nothing
     "Dinosaurs extinct"
     "Mammals take over land & sea"
     [text|
-    |]
-    "",
+    An asteroid more than 6 miles across strikes the Yucatan Peninsula, triggering the fifth mass extinction in the world’s history.
+
+    Some of the debris thrown into the atmosphere returned to Earth, the friction turning the air into an oven and sparking forest fires as it landed all over the world. The intensity of the heat pulse gave way to a prolonged impact winter, the sky blotted out by soot and ash as temperatures fell.
+
+    More than 75 percent of species known from the end of the Cretaceous period, 66 million years ago, didn’t make it to the following Paleogene period. The geologic break between the two is called the K-Pg boundary, and beaked birds were the only dinosaurs to survive the disaster.|]
+    [text|
+    https://www.smithsonianmag.com/science-nature/why-birds-survived-and-dinosaurs-went-extinct-after-asteroid-hit-earth-180975801/,
+    https://www.amnh.org/shelf-life/six-extinctions
+    |],
 
     CalendarEntry (27.5 & millionYearsAgo) Nothing
     "Apes and monkeys split"