Oil Pan Seals ??
When the rear main seal is installed on the motor,two rubber strips of 1/8 seals are laid down in between the main cap and the block to stop any leakage.The pieces you see are the outer parts of that seal.You can simple run a bead of silicone to replace the area where the seal would have been.Look at the rear main cap to be sure the seel did not pull out of the cap,and reinstall the pan,Mrmopartech