The myodural bridge exists in viper snakes

The myodural bridge(MDB)is a connection between the suboccipital muscles and cervical dura mater in the posterior atlanto occipital interspace found in mammals.Specifically,we focused on the Gloydius Shedaoensis,a species of Agkistrodon that only found on Shedao Island located in the southeastern sea of Dalian City in China.Six head and neck up to the sixth vertebra(V6)cadavers of Gloydius Shedaoensis were examined in this study.Three were used for anatomical dissection and the remaining three were used for histological analysis.The spinalis muscle originated from the posterior edge of the supraoccipital bones and the dorsal facet of exocciput,extended on both sides of the spinous process covering the spine,merging with semispinalis muscle.