2019-10-08 15:41:35.0 [tstevens] Insert Concept
add broader relation (UPPER [d3928482-e056-4d2d-ae5a-1e7097099c2b,369237] - CRETACEOUS
[0d7a2c62-d0b0-4a13-8412-d7cc8d68aeff,336049]);
|
|
2019-10-09 07:13:31.0 [tstevens] Insert Concept
add narrower relation (UPPER [d3928482-e056-4d2d-ae5a-1e7097099c2b,369237] - MAASTRICHTIAN
[8ce20eea-74f0-40cd-b611-4686427c5fa4,369249]);
|
|
2019-10-09 07:13:52.0 [tstevens] Insert Concept
add narrower relation (UPPER [d3928482-e056-4d2d-ae5a-1e7097099c2b,369237] - CAMPANIAN
[96713563-fdf4-4e05-ad85-36cf66a74260,369253]);
|
|
2019-10-09 07:14:16.0 [tstevens] Insert Concept
add narrower relation (UPPER [d3928482-e056-4d2d-ae5a-1e7097099c2b,369237] - SANTONIAN
[2fc19a25-4320-4513-a4a3-f20548ed1daa,369257]);
|
|
2019-10-09 07:15:24.0 [tstevens] Insert Concept
add narrower relation (UPPER [d3928482-e056-4d2d-ae5a-1e7097099c2b,369237] - CONIACIAN
[f431ccfe-5f30-4faa-84d0-4621fb602f10,369261]);
|
|
2019-10-09 07:16:43.0 [tstevens] Insert Concept
add narrower relation (UPPER [d3928482-e056-4d2d-ae5a-1e7097099c2b,369237] - TURONIAN
[4912ab7c-dd62-48df-975c-e3e107a4b09b,369265]);
|
|
2019-10-09 07:17:30.0 [tstevens] Insert Concept
add narrower relation (UPPER [d3928482-e056-4d2d-ae5a-1e7097099c2b,369237] - CENOMANIAN
[66543c1a-4855-4ded-a610-c38a80cf158a,369269]);
|
|
2019-10-09 09:09:32.0 [tstevens]
insert Definition (id: null
text: The Upper Cretaceous is the last geological epoch in the Cretaceous. It began
100.5 million years ago, and ended 66 million years ago.
The Cretaceous is traditionally divided into Lower Cretaceous (early), and Upper Cretaceous
(late), because of the different rocks. The rocks reflect the conditions in which
they were formed.
The Upper Cretaceous is the chalk. It is composed of countless millions of calcareous
(CaCO3) plates called coccoliths. They are so small they can only just be seen with
a light microscope; details require an electron microscope. The plates are formed
by single-celled planktonic algae called coccolithophores, and were laid down in the
off-shore seas.
The only other rock found in chalk is the flint, which is siliceous (silica, SiO2).
This derives from those algae and animals which have skeletons of silica.
The Cretaceous was the last period when dinosaurs were the dominant land animals.
Triceratops, Tyrannosaurus and Velociraptor lived at this time. The huge Mosasaurus
was the dominant marine predator. In the Cretaceous period, birds became more diverse.
Flowering plants developed more, and became the dominant plants on land. The Upper
Cretaceous ended with the K/T extinction event.
language code: en);
|
|
2020-01-06 07:59:29.0 [tstevens] Rename Concept
update PrefLabel (LATE);
|
|