Need help with "IF"- functions and other

Hello,
i need to evaluate a paleo diversity database in RStudio but to be able to do the i need to "clean up" the database first. I do not have much excel experience yet so please excuse my probably mundane questions/requests.

1. IF Function
In the Database longitudinal and latidutinal coordinates are not provided uniformly. They're usually given in degrees but sometimes they're missing the decimal point. (50.24° = 50240)
My idea was to solve this by using an IF function as follows:

IF X > 90 or X< -90 divide by 1000 else return original value

i've already tried to do it myself using the help function but it wouldnt work.


2. Filtering for a value
The ranks to which certain fossils are characterized vary (e.g. Kingdom, Genus, Species)
I need to get rid of everything (all rows) that do not have the value "genus or species" in one of their columns
I also need a function that gets rid of all rows that have blanks/empty cells in a specific column.

3. Dividing values sperated by a space
If species are given like "Tetradium huronense" i need to get rid of everything after the genus (e.g. Tetradium huronense -> Tetradium)
maybe this could be done with a split funtion of some sort


4. Filter to get a list of all contained values
The lithology in which those fossils were found is given for most of the fossils. To evaluate i need to get a list that contains all entered values for a certain column (e.g. 5000*carbonate, 2500*shale etc.)


Please help me solve this by giving step by step instructions since all ive done so far using excel was plotting graphs and doing some simple automated calculations.


Thanks in advance
afridelle

Im sorry,
i wasnt able to edit the attachments in the first post so i reposted it.
couldnt think of any short title thats more suitable