geo

Draw or explain the difference between gastropods and ammonoids. How will you tell them apart on the lab practical? What phyla are gastropods from? What phyla are ammonoids from? When did gastropods live? When did ammonoids live?

Both gastropods and ammonoids are from the phylum Mollusca. Both have a spiral shape. In gastropods, the spiral has a vertical component, like the spiral shape of a soft serve ice cream cone. The ammonoid spiral is two dimensional, like a coiled rope. Additionally some ammonoid specimens show. sutures separating individual chambers. Gastropods lived from the Cambrian to today. Ammonoids have lived from the Ordovician to the Cretaceous.

explain the difference between a goniatite ammonoid suture pattern, a ceratitic ammonoid suture pattern, and an ammonitic ammonoid suture pattern. (How will you tell them apart on the lab practical). When did each of these ammonoids live?

Goniatic ammonoid suture pattern is a simple pattern of lobes and saddles. The ceratitic ammonoid suture pattern has sutures only on the lobes. The ammonoitic suture pattern is complex, where each lobe and saddle is covered with a fractal like, repeating branching pattern. Goniatitic: Paleozoic. Ceratitic: Triassic. Ammonitic: Jurassic - Cretaceous

explain the difference between rugose corals and scleractinian corals. How will you tell them apart on the lab practical? What phyla are corals from? When did each of these corals live?

Rugose and scleractinian corals both have septa. Neither have tabula. The septa of rugose corals all meet in the middle. The septa of scleractinian corals do not all meet in the middle, some appear to be short spikes pointing toward the middle but not connecting. Both rugose and scleractinian corals can be colonial or solitary. Rugose corals live from the Middle Ordovician to the Permian. Scleractinian corals live from the Middle Triassic until today! They are both in the phylum Cnidaria.

What are the two kinds of echinoids? How will you tell them apart on the lab practical? What phylum do they belong to? When did echinoids live?

Sand dollar = pita bread (flat), sea urchin = beach ball. Both have 5-fold symmetry. Phylum- =Echinodermata. Cambrian to today

explain the difference between colonial tabulate corals and colonial rugose corals and solitary rugose corals. How will you tell them apart on the lab practical? What phylum are corals from? When did each of these corals live?

Tablulate corals have tabula, horizontal tables or shelves of carbonate that you can see in a cross section view. Some tabulate corals form a chain-like pattern of polyps. All tabulate corals are colonial. Rugose corals have septa. These septal lines extend from the perimeter of the coral wall and meet in the center. Tabulate corals do not have these septa and rugose corals do not have tabula. Rugose corals can be colonial or solitary. They are both in the phylum Cnidaria. Rugose and tabulate corals live from the Middle Ordovician to the Permian.

Three types of corals and their phylum.

Tabulate corals: Paleozoic Rugose corals: Paleozoic Scleractinian corals: Mesozoic and Cenozoic Phylum Cnidaria

Fusulinids

huge Foraminifera (largest single-celled protist). Pennsylvanian to end- Permian. Excellent Index fossils for late Paleozoic time. Make up the bulk of some late Paleozoic rocks.