Rare Finding of a Full Nuchal Ligament Lamellae With Attachment Points From C2-C7 in One Australian Stock Horse.

The research discovered an uncommon trait in an Australian Stock Horse, whereby its neck ligament extended from the second to seventh cervical vertebrae (C2-C7). This trait is more commonly seen in ancestral horse breeds and has been lost in most modern horses.

The Discovery

• The study focused on a key anatomical feature of horses – the nuchal ligament lamellae (NLL), a ligament in the neck that usually attaches from the second to the fifth cervical vertebrae (C2-C5) in most modern horses.
• In this study, a remarkable finding was made – the discovery of a full NLL that extended from C2-C7 in one Australian Stock Horse, a trait that is considered very rare in modern horse breeds.

Findings from Other Breeds

• This full NLL attachment has only been confirmed in descendants of the ancient wild horse species Equus ferus ferus, specifically the Dutch Konik and Bosnian Mountain Horse.
• A survey of 55 unrelated horses of mixed breeds showed that the majority (52 out of 55) had the usual attachment from C2-C5.
• Only a Welsh Cob, the Australian Stock Horse, and a Dutch Konik showed different attachment points, with the first two having a complete NLL from C2-C7, and the Welsh Cob having attachment points from C2-C6.

Implications and Theories

• The researchers propose that the presence of the full NLL in the one Australian Stock Horse may be a residual trait from the Waler horses, an ancestral breed that contributed to the initial development of the Australian Stock Horse breed.
• This idea is based on previous findings that suggest the loss of NLL attachment at C6 and C7 happened after horses were domesticated.
• Given the rare occurrence of a complete NLL in a domesticated equine suggests that there might be other horses carrying this unique trait, and thus, it opens up a possibility for its preservation in future generations.