Thank you for the opportunity to help you with your question!
Archaeornithipus is an ancient bird that had no hallux.
Archaeornithipus was a genus of large bird ichnogenus discovered in Spain. The tracks date back to the Berriasian, making them among the oldest bird trace
Althought the New World Vultures with their straight toes and short hallux cannot grip or carry anything and would be limited to pinning small animals down with their feet and dispatching them with their beak.
Please let me know if you need any clarification. I'm always happy to answer your questions.
Nov 12th, 2015
From the picture, I notice three long toes with sharp talons. The hind toe called the "hallux" looks simply like a talon. The only bird that seems to lack a hallux is the Archaeornithipus. It lived during the upper Jurassic to lower cretaceous period.
Archaeornithipus footprints were long, slender, clawed digits. Digits are keel-shaped. Digit III is the longest. Hallux (digit I) is very conspicuous and forms a 120-180° angle with digit III.