HOME | DD

Description

Another theropod, already the fourth in this year. This is tyrannosauroidean Alectrosaurus olseni from the late Cretaceous (presumably, Campanian) of Mongolia. The holotype, discovered by Geordie Olsen in 1923, consisted, in addition to some other fragments, almost a complete hindlimb. The animal was related to the so-called "deinodonts", i.e. the group now called Tyrannosauridae. However, the available material is not sufficient to accurately classify animal, so Alectrosaurus is currently characterized as a non-tyrannosauroid tyrannosauroid (Loewen et al. 2013). Among the later specimens can be noted fragments of the skull, found separately from each other. Once it was believed that Alectrosaurus had well-developed hands, but later the specimens that served as the basis for this version were transferred to therizinosaurids. Therefore, the true length of the hands is unknown, but it can be assumed that there were only two functional fingers.

Very long distal parts of the hindlimbs, showing arctometatarsal condition, indicate a swift runner. The general description paints a picture of a pursuit hunter.

This reconstruction shows an extensive protofeather covering, apparently typical for non-tyrannosaurids tyrannosaurids. If tyrannosaurids have lost their filaments, the question is, when did they do it? This question I raised in the description of last year's reconstruction of the North American Appalachiosaurus. Naked legs and head can have thermoregulatory value for active running animal in hot climate.

EDIT: Scanned version.

Technical pencil HB, 2019.

Description

Another theropod, already the fourth in this year. This is tyrannosauroidean Alectrosaurus olseni from the late Cretaceous (presumably, Campanian) of Mongolia. The holotype, discovered by Geordie Olsen in 1923, consisted, in addition to some other fragments, almost a complete hindlimb. The animal was related to the so-called "deinodonts", i.e. the group now called Tyrannosauridae. However, the available material is not sufficient to accurately classify animal, so Alectrosaurus is currently characterized as a non-tyrannosauroid tyrannosauroid (Loewen et al. 2013). Among the later specimens can be noted fragments of the skull, found separately from each other. Once it was believed that Alectrosaurus had well-developed hands, but later the specimens that served as the basis for this version were transferred to therizinosaurids. Therefore, the true length of the hands is unknown, but it can be assumed that there were only two functional fingers.

Very long distal parts of the hindlimbs, showing arctometatarsal condition, indicate a swift runner. The general description paints a picture of a pursuit hunter.

This reconstruction shows an extensive protofeather covering, apparently typical for non-tyrannosaurids tyrannosaurids. If tyrannosaurids have lost their filaments, the question is, when did they do it? This question I raised in the description of last year's reconstruction of the North American Appalachiosaurus. Naked legs and head can have thermoregulatory value for active running animal in hot climate.

EDIT: Scanned version.

Technical pencil HB, 2019.