Subspecies
Different subspecies can usually be distinguished by the relative lengths and shapes of their lacrimal bones. S. scrofa cristatus and S. scrofa vittatus have shorter lacrimal bones than European subspecies. Spanish and French boar specimens have 36 chromosomes, as opposed to wild boar in the rest of Europe which possess 38, the same number as domestic pigs. Boars with 36 chromosomes have successfully mated with animals possessing 38, resulting in fertile offspring with 37 chromosomes.
Four subspecies groups are generally recognised:
Read more about this topic: Wild Boar