Fossils of 540 million years ...

                                 Trilobites
Trilobites
They appeared about 540 million years ago. They lived in the Paleozoic seas and became extinct some 250 million years ago.

Its fossils are very abundant on all continents, especially north of Africa.
Its name means: Trilobulated. Some 4000 species have been described.

Photos of: Felix Collantes

Dinos, origin

Origin of dinosaurs

From the Proterosúquidos (253 to 245 million years), the Arcosaurios arose (245 to 208 million years).
The Archosaurs evolved and gave rise to the Dinosaurs that appeared during the Triassic geological period (231 to 243 million years).



Most dinosaurs became extinct some 66 million years ago.



The man did not get to live with these species, since his appearance was much more recent.

The representatives or descendants of the dinosaurs, are the current birds.




the largest dinosaur could have reached a length of 58 meters and 9.25 meters in height

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There were dinosaurs of small size, as for example the Xixianykus was about 50 centimeters long.


The Pterosaurs had membranous wings   




Archeaurus with its body covered with feathers.

What are sunspots?

Sunspots are regions of the Sun, with less temperature than the rest of the solar surface. In addition, they have a high magnetic activity.
The absence of sunspots has a negative effect on the propagation of electromagnetic waves, causing broadcast transmissions, especially in short waves, to be affected and become unstable.
I like amateur radio (radio amateur), I notice in the low possibility of contacts with distant stations.
We are currently in the SS observation cycle 24, since it began to carry a data about 250 years ago.
The cycles of SS. Have an average duration of about 11 years. 
Compare the size of the Earth with that of a sunspot, in the graphic above.