[D] Deinocheirus mirificus [sG] [T]
Describer
Osmolska & Roniewicz, 1970
Time
Cretaceous Late ?Campanian Maastrichtian
Classification
Saurischia Theropoda Tetanurae Coelurosauria
Diet
Carnivore
Fossilsite
Nemegt Formation, Omnogov, Mongolia
Length
13 meter
Info
Genus - Typespecies
Forelimb elements
Pectoral girdle and forelimbs of a single specimen. Deinocheirus mirificus was undoubtedly a gigantic creature, with forlimbs that were 2.4 m. long. The gigantic size of the forelimb and the girdle elements of Deinocheirus prompted Osmolska and Roniewiecz , 1970 to assign this genus to a new family [Deinocheiridae], within the Coelurosauria.
Somewhat later Rozdestvensky (1970) noted that carnosaurs generally tend to exhibit forelimb reduction, rather than extreme elongation, and compared Deinocheirus to ornithomimids; this latter view has been supported by Ostrom (1972) et al.; Galton (1982) & Barsbold (1976) proposed a new infraorder. [Deinocheirosauria], to include both the [Deinocheiridae] and [Therizinosauridae- Therizinosauroidea]
However, it would appaer that such a suggestion is untenable. The metacarpals and fingers are subequel in length and have massive, curved ungual phalanges. It is generally assigned to the Ornithomimosauria because the resemblance of manual and forlimb bones, and unfurtunately nothing else is known of this dinosaur.
(ZPAL MgD-I/6) (10-13 m; 2.4-4.3 tons) two ceratobranchials, three vertebral fragments, seven partial dorsal ribs, gastralia fragments, nearly complete scapulacoracoids (1.53 m), humeri (938 mm), radii (630 mm), ulnae (688 mm), metacarpal I (214, 220 mm), phalanx I-1 (320 mm), manual ungual I, metacarpal II (230 mm), phalanx II-1 (140 mm), phalanx II-2 (226, 229 mm), manual ungual II (196 mm), metacarpal III (246, 245 mm), phalanx III-1 (110, 105 mm), phalanx III-2 (104, 100 mm), phalanx III-3 (186, 182 mm), manual ungual III (Osmolska and Roniewiecz 1967) The estimates are based on various ornithomimosaur species. [M.Mortimer]
Barsbold, 1983
Holotype
PST GIN AN MNR no. 100/18; right and left humeri, right and left forearm, right and left carpus, manual phalanges (right ungual phalanx is missing).
Description
Scapula length 1190 mm (left side), with moderately widened ventral part, moderately large acromial process, and narrowed, elongated dorsal ramus. The posterior of the thickened edge of the ventral widening becomes thinner anteriorly. The dorsal ramus of the scapula has more or less parallel anterior and posterior edges. The coracoid is 340 mm long and moderately widened; its external edge is slightly convex.
The coracoid foramen is rounded on the lateral edge, and has the appearance of a deep furrow on the medial surface. The attachment site for the biceps muscle corresponds to a weakly expressed, gently sloping convexity. The glenoid cavity is shallow, and slightly laterally directed. The supraglenoid thickening has the appearance of a slight concavity. The humerus is elongated (938 mm), with a relatively thin shaft and moderately widened proximal end.
The deltopectoral crest is relatively low, extending approximately one-third the length of the entire bone from the proximal end. The distal end of the humerus is slightly widened, and somewhat flattened anteroposteriorly. The condyles are positioned more distally. The epicondyles are weakly developed. The ulna is elongate (688 mm), relatively slender, and with moderately widened extensions. The proximal articular surface of the bone is slightly differentiated, and participates in the formation of a shallow, weakened elbow joint.
The radius is 630 mm in length, slender, weakly curved anteriorly, and has insignificantly widened articular ends. The metacarpus consists of three elements. Metacarpal I is 214 mm long, is the most shortened, massive, flattened dorsoventrally, and has two sections of the proximal articular surface. The distal articular head is asymmetrical, so its cavity is displaced ventrally. Medially, the lateral-connecting cavity is deep, while laterally it is shallow.
Metacarpal II is 230 mm long, with a slightly concave proximal articular surface with a quadrilateral outline. The distal articular head is convex, with a ventrally displaced, weakly expressed sagittal cavity. The lateralconnecting cavity is fairly deep. Metacarpal III is 246 mm long and the [thinnest], with a three-sectioned articular surface. The distal articular head has a larger lateral condyle and a deep sagittal cavity. The medial-connecting cavity is more shallow than the lateral one. Digit I is more massive, with an elongated phalanx 1 (320 mm). Its proximal articular surface is concave, and the distal head is symmetrically divided by a furrow with deep lateral-connecting cavities.
The basal phalanges of digits II and III are considerably shortened (140 mm and 110 mm, respectively), and have concave proximal surfaces and symmetrical distal heads with shallow lateral-connecting cavities. Phalanx 2 of digit III is shorter (104 mm) and [thinner] than phalanx 1, with a convex sagittal crest of the proximal articular surface.
The penultimate phalanges of digits II and III (226 mm and 186 mm, respectively) have narrow, elongated shafts that form well-developed, ginglymoid articulations. The ungual phalanges are massive, laterally compressed, highly curved, pointed distally, and slightly decreasing in size in digit order. The proximal articular surfaces have convex crests.
Discussion
Presently known large ungual phalanges, found separately (Ricqles, 1967; Rozhdestvensky, 1970), are more or less similar to those of [deinocheirosaurs,] although they have apparently differences in details of shape and construction. The large sizes of separately found phalanges have not completely decided the question of these similarities and differences. Mostly likely, there existed gigantic carnivorous dinosaurs with unusually large claws and non-reduced forelimbs that were possibly not classified with [deinocheirosaurs] Deinocheirus probably surpassed Chilantaisaurus maortuensis (Hu, 1964) in the size of the humerus and also in its basic distinguishing features – the configuration and dimensions of the deltopectoral crest, etc.
The supposed absence of the pulley-type carpus in deinocheirids is confirmed by the peculiarities of the construction of the proximal articular surfaces of the metacarpals, as well as in the general functional weakening of the forelimb, which in this is reminiscent of ornithomimids and tyrannosaurids, in which the pulley carpus is [also] not developed.
Source: Polyglot Paleontologist
Osmolska & Roniewicz, 1970
Time
Cretaceous Late ?Campanian Maastrichtian
Classification
Saurischia Theropoda Tetanurae Coelurosauria
Diet
Carnivore
Fossilsite
Nemegt Formation, Omnogov, Mongolia
Length
13 meter
Info
Genus - Typespecies
Forelimb elements
Pectoral girdle and forelimbs of a single specimen. Deinocheirus mirificus was undoubtedly a gigantic creature, with forlimbs that were 2.4 m. long. The gigantic size of the forelimb and the girdle elements of Deinocheirus prompted Osmolska and Roniewiecz , 1970 to assign this genus to a new family [Deinocheiridae], within the Coelurosauria.
Somewhat later Rozdestvensky (1970) noted that carnosaurs generally tend to exhibit forelimb reduction, rather than extreme elongation, and compared Deinocheirus to ornithomimids; this latter view has been supported by Ostrom (1972) et al.; Galton (1982) & Barsbold (1976) proposed a new infraorder. [Deinocheirosauria], to include both the [Deinocheiridae] and [Therizinosauridae- Therizinosauroidea]
However, it would appaer that such a suggestion is untenable. The metacarpals and fingers are subequel in length and have massive, curved ungual phalanges. It is generally assigned to the Ornithomimosauria because the resemblance of manual and forlimb bones, and unfurtunately nothing else is known of this dinosaur.
(ZPAL MgD-I/6) (10-13 m; 2.4-4.3 tons) two ceratobranchials, three vertebral fragments, seven partial dorsal ribs, gastralia fragments, nearly complete scapulacoracoids (1.53 m), humeri (938 mm), radii (630 mm), ulnae (688 mm), metacarpal I (214, 220 mm), phalanx I-1 (320 mm), manual ungual I, metacarpal II (230 mm), phalanx II-1 (140 mm), phalanx II-2 (226, 229 mm), manual ungual II (196 mm), metacarpal III (246, 245 mm), phalanx III-1 (110, 105 mm), phalanx III-2 (104, 100 mm), phalanx III-3 (186, 182 mm), manual ungual III (Osmolska and Roniewiecz 1967) The estimates are based on various ornithomimosaur species. [M.Mortimer]
Barsbold, 1983
Holotype
PST GIN AN MNR no. 100/18; right and left humeri, right and left forearm, right and left carpus, manual phalanges (right ungual phalanx is missing).
Description
Scapula length 1190 mm (left side), with moderately widened ventral part, moderately large acromial process, and narrowed, elongated dorsal ramus. The posterior of the thickened edge of the ventral widening becomes thinner anteriorly. The dorsal ramus of the scapula has more or less parallel anterior and posterior edges. The coracoid is 340 mm long and moderately widened; its external edge is slightly convex.
The coracoid foramen is rounded on the lateral edge, and has the appearance of a deep furrow on the medial surface. The attachment site for the biceps muscle corresponds to a weakly expressed, gently sloping convexity. The glenoid cavity is shallow, and slightly laterally directed. The supraglenoid thickening has the appearance of a slight concavity. The humerus is elongated (938 mm), with a relatively thin shaft and moderately widened proximal end.
The deltopectoral crest is relatively low, extending approximately one-third the length of the entire bone from the proximal end. The distal end of the humerus is slightly widened, and somewhat flattened anteroposteriorly. The condyles are positioned more distally. The epicondyles are weakly developed. The ulna is elongate (688 mm), relatively slender, and with moderately widened extensions. The proximal articular surface of the bone is slightly differentiated, and participates in the formation of a shallow, weakened elbow joint.
The radius is 630 mm in length, slender, weakly curved anteriorly, and has insignificantly widened articular ends. The metacarpus consists of three elements. Metacarpal I is 214 mm long, is the most shortened, massive, flattened dorsoventrally, and has two sections of the proximal articular surface. The distal articular head is asymmetrical, so its cavity is displaced ventrally. Medially, the lateral-connecting cavity is deep, while laterally it is shallow.
Metacarpal II is 230 mm long, with a slightly concave proximal articular surface with a quadrilateral outline. The distal articular head is convex, with a ventrally displaced, weakly expressed sagittal cavity. The lateralconnecting cavity is fairly deep. Metacarpal III is 246 mm long and the [thinnest], with a three-sectioned articular surface. The distal articular head has a larger lateral condyle and a deep sagittal cavity. The medial-connecting cavity is more shallow than the lateral one. Digit I is more massive, with an elongated phalanx 1 (320 mm). Its proximal articular surface is concave, and the distal head is symmetrically divided by a furrow with deep lateral-connecting cavities.
The basal phalanges of digits II and III are considerably shortened (140 mm and 110 mm, respectively), and have concave proximal surfaces and symmetrical distal heads with shallow lateral-connecting cavities. Phalanx 2 of digit III is shorter (104 mm) and [thinner] than phalanx 1, with a convex sagittal crest of the proximal articular surface.
The penultimate phalanges of digits II and III (226 mm and 186 mm, respectively) have narrow, elongated shafts that form well-developed, ginglymoid articulations. The ungual phalanges are massive, laterally compressed, highly curved, pointed distally, and slightly decreasing in size in digit order. The proximal articular surfaces have convex crests.
Discussion
Presently known large ungual phalanges, found separately (Ricqles, 1967; Rozhdestvensky, 1970), are more or less similar to those of [deinocheirosaurs,] although they have apparently differences in details of shape and construction. The large sizes of separately found phalanges have not completely decided the question of these similarities and differences. Mostly likely, there existed gigantic carnivorous dinosaurs with unusually large claws and non-reduced forelimbs that were possibly not classified with [deinocheirosaurs] Deinocheirus probably surpassed Chilantaisaurus maortuensis (Hu, 1964) in the size of the humerus and also in its basic distinguishing features – the configuration and dimensions of the deltopectoral crest, etc.
The supposed absence of the pulley-type carpus in deinocheirids is confirmed by the peculiarities of the construction of the proximal articular surfaces of the metacarpals, as well as in the general functional weakening of the forelimb, which in this is reminiscent of ornithomimids and tyrannosaurids, in which the pulley carpus is [also] not developed.
Source: Polyglot Paleontologist