Lumbricals of the foot phalanges. All four lumbricals insert into extensor hoods of the phalanges, thus creating extension at the inter-phalangeal (PIP and DIP) joints. However, as the tendons also pass inferior to the metatarsal phalangeal (MTP) joints it creates flexion at this joint. Absence of one or more; doubling of the third or fourth even the fifth. Insertion partly or wholly into the first phalanges. The most medial lumbrical is innervated by the medial plantar nerve while the remaining three lumbricals are supplied by the lateral plantar nerve. Lumbricals of the foot The lumbricals are four small skeletal muscles, accessory to the tendons
Ostromia addition, the ungual (claw) of the first digit of the hand is smaller than the corresponding first metacarpal, while in "Archaeopteryx" the claw is larger. The Haarlem specimen's metatarsals are also estimated to be proportionally longer than those of "Archaeopteryx" specimens. In addition, the Haarlem specimen shares several features with "Anchiornis". Most notably, they both have longitudinal furrows on the top and bottom sides of their manual phalanges (finger bones). While such structures can be a result of collapsed or broken bones (as is the case in several "Archaeopteryx" specimens), the straight, smooth edges of the furrows in "Ostromia" and