The trunks of Palm trees do not get thicker as they age; rather, they simply grow taller. Some Palms have trunks that are as skinny as pencils. Fossil Palm trees date back 100 million years to the Jurassic Era. Muslims regard the Date Palm as the tree of life, as its roots can be traced back more than 5,000 years.
At last count, there were more than 9,000 species of segmented worms on the planet today. Some of the most common types of segmented worms include earthworms, leeches, and sandworms. Earthworms make up the largest and most diverse group of segmented worms in the world. In all, there are more 2,700 different types of earthworms living in every corner of the earth today.
1 They have a circulatory system and a digestive system. 2  Flatworms, roundworms, and segmented worms are all invertebrates. 3  Some species of each type of worm are free-living, meaning they are not dependent on another organism for food. 4  Segmented worms are the most complex animals of these three invertebrates. Students will then continue with their Internet research to compare flatworms, roundworms, and segmented worms by completing the Worm Comparison worksheet. 2  They should use their research to find more information in order to describe how these three types of worms are similar and how they are different.