[D] Azendohsaurus [sG]
Describer
Dutuit, 1972
Time
Triassic Late Carnian
Classification
Saurischia Sauropodomorpha Prosauropoda Thecodontosauridae
Diet
Herbivore
Fossilsite
Morocco
Typespecies
Azendohsaurus laaroussi (1)
Length
1,8 meter
Info
Azendohsaurus (Dutuit, 1972) > Azendohsaurus laaroussi (1) (Dutuit, 1972 partim)
Named for the village of Azendoh, near the fossil deposit in the Atlas Mountains region of Marrakesh, Morocco
According to Jalil and Knoll (2002) JVP, [abstract] Azendohsaurus laaroussii is an archosaur from the Carnian of Morocco Argana Basin - Argana Formation) originally described on the basis of cranial elements (maxillae, dentaries, and isolated teeth). It was considered at first a close relative of the ornithischian Fabrosaurus australis from the Hettangian of Southern Africa.
This view was nevertheless rapidly challenged. In fact, Azendohsaurus has been alternatively considered a prosauropod (or a basal sauropodomorph) or a taxon based on composite material (prosauropod + ornithischian). Yet, the second opinion has been demonstrated to be wrong and a newly prepared material casts doubt on the assumed dinosaurian nature of Azendohsaurus.
This bears a particular importance since this taxon is usually considered as one of the earliest dinosaurs. The new material is from the locality XVI of Dutuit’s nomenclature, i.e. the locus typicus of Azendohsaurus laaroussii.
It consists of various disarticulated post-cranial remains (presacral vertebrae, elements of the pectoral and pelvic girdles, and elements of the forelimbs and hind limbs) found closely associated with Azendohsaurus cranial fragments.
No dinosaurian synapomorphy is found in this material that, in contrast, shows an assortment of plesiomorphic character-states suggesting a phylogenetic position outside the Dinosauria. Four of these, namely an imperforate acetabulum, the absence of a brevis fossa on the ilium, the fourth trochanter of the femur situated very proximally, and the head of the femur not distinctly set off from the shaft, may be considered to be the most significant. Since these new post-cranial remains identified as Azendohsaurus laaroussii are disarticulated, this attribution is merely an inference from taphonomic circumstances.
For that reason, discovery of articulated material is needed to settle convincingly the phylogenetic position of this taxon within the Ornithodira. Hopefully the Malagasy aff. Azendohsaurus (Carnian) material, still under study, comprises such specimens.
Dutuit, 1972
Time
Triassic Late Carnian
Classification
Saurischia Sauropodomorpha Prosauropoda Thecodontosauridae
Diet
Herbivore
Fossilsite
Morocco
Typespecies
Azendohsaurus laaroussi (1)
Length
1,8 meter
Info
Azendohsaurus (Dutuit, 1972) > Azendohsaurus laaroussi (1) (Dutuit, 1972 partim)
Named for the village of Azendoh, near the fossil deposit in the Atlas Mountains region of Marrakesh, Morocco
According to Jalil and Knoll (2002) JVP, [abstract] Azendohsaurus laaroussii is an archosaur from the Carnian of Morocco Argana Basin - Argana Formation) originally described on the basis of cranial elements (maxillae, dentaries, and isolated teeth). It was considered at first a close relative of the ornithischian Fabrosaurus australis from the Hettangian of Southern Africa.
This view was nevertheless rapidly challenged. In fact, Azendohsaurus has been alternatively considered a prosauropod (or a basal sauropodomorph) or a taxon based on composite material (prosauropod + ornithischian). Yet, the second opinion has been demonstrated to be wrong and a newly prepared material casts doubt on the assumed dinosaurian nature of Azendohsaurus.
This bears a particular importance since this taxon is usually considered as one of the earliest dinosaurs. The new material is from the locality XVI of Dutuit’s nomenclature, i.e. the locus typicus of Azendohsaurus laaroussii.
It consists of various disarticulated post-cranial remains (presacral vertebrae, elements of the pectoral and pelvic girdles, and elements of the forelimbs and hind limbs) found closely associated with Azendohsaurus cranial fragments.
No dinosaurian synapomorphy is found in this material that, in contrast, shows an assortment of plesiomorphic character-states suggesting a phylogenetic position outside the Dinosauria. Four of these, namely an imperforate acetabulum, the absence of a brevis fossa on the ilium, the fourth trochanter of the femur situated very proximally, and the head of the femur not distinctly set off from the shaft, may be considered to be the most significant. Since these new post-cranial remains identified as Azendohsaurus laaroussii are disarticulated, this attribution is merely an inference from taphonomic circumstances.
For that reason, discovery of articulated material is needed to settle convincingly the phylogenetic position of this taxon within the Ornithodira. Hopefully the Malagasy aff. Azendohsaurus (Carnian) material, still under study, comprises such specimens.