CT Scanners. Usually this instrument is used in the medical field, but it is also used in paleontology. In paleontology these are used to identify the reptiles and animals that are found in rocks without actually cracking the rocks.
4. You do not file a return: Keep records indefinitely. 5. You file a claim for credit or refund after you file your return: Keep records for three years from the date you filed your original return or two years from the date you paid the tax, whichever is later. 6. You file a claim for a loss from worthless securities or bad debt deduction: Keep records for seven years. 7.
Some special circumstances require that tax records be kept longer than four years. If you failed to report income, and it is more than 25 percent of the gross income you reported; then you need to keep the records relating to that income for six years.