Diplodocoids followed the general body-plan of sauropod dinosaurs: a big oval torso, supported on four pillar-like legs, a long neck with a small head, and a long tail. Their snouts were long, had nostrils on top, and peg-like teeth for stripping vegetation. The rear legs were a bit longer than the front ones, and strong enough to support a rearing posture while standing. Each of the front feet had a single sharp claw projecting inwards.
There is evidence that many species of diplodocoid gathered in herds, usually with animals of similar age.
Whip Tails
The long, whip-like tips of diplodocoid tails have prompted speculation that they might have been used to strike other dinosaurs, or produce a loud noise by moving fast enough to break the sound barrier.
Used as a weapon, the tail can strike into side and rear hexes, with a reach determined by the creature’s SM (Size Modifier and Reach, GURPS Basic Set, p. 402). It does the same damage as trampling.
When used as a noise-maker, the tail produces about 200 dB, which is enough to rupture eardrums at close range. At 1 yard, roll HT−5 to avoid Deafness for 1d Months. If successful, roll HT−7 to avoid Hard of Hearing for 1 day. Each doubling of distance gives +1 to resist. The sound can be heard on an unmodified hearing roll up to 32 miles away. See GURPS Powers: Enhanced Senses, p. 21 for further details.
Apatosaurs
Apatosaurus and Brontosaurus had especially short torsos and extra-long tails. A fleshy ridge ran down their spines, tallest above their hips and may have been topped with short spikes. Their necks were thick, studded with keratinous knobs, and well suited to smashing into each other.
They lived in western Laurasia (now the Western United States) during the late Jurassic. They are believed to have been grazers, eating mostly ferns and other low vegetation.
Brontosaurus excelsus
ST 71;
DX 9;
IQ 2;
HT 11.
HP 71;
Will 10;
Per 10;
FP 11;
Speed 3.00;
Dodge 6;
Move 5.
SM +7 (20 hexes), 44,000 lbs.
Claw (9): 8d−1 impaling. Reach C-2.
Neck strike (9): 8d crushing. Reach 1-6. Front only.
Trample (9): 8d crushing.
Traits: Bad Sight (Low Resolution); Chummy; Discriminatory Smell; DR 4 (Tough Skin); Enhanced Move 1 (Ground Speed 10; Costs Fatigue, 1 FP/Second); Long Neck 2; Peripheral Vision; Quadruped; Weak Bite; Wild Animal.
Skills: Survival (Plains)-12.
Apatosaurus ajax (48,000 lbs.) increases ST and HP to 73 (damage 8d with claw, 8d+1 with neck or trample). A. parvus (33,000 lbs.) reduces ST and HP to 64 (damage 7d with claw, 7d+1 with neck or trample).
Dicraeosaurids
Dicraeosaurus hansemanni and D. sattleri lived in eastern Gondwana, now East Africa, during the late Jurassic. They had relatively short necks and some kind of hump or short sail above their hips. Amargasaurus lived in south-western Gondwana, now South America, during the early Cretaceous. It had similar anatomy, with the addition of dramatic spikes on the back of its neck.
Dicraeosaurus hansemanni
ST 44;
DX 10;
IQ 2;
HT 11.
HP 44;
Will 10;
Per 10;
FP 11;
Speed 3.00;
Dodge 6;
Move 5.
SM +6 (12 hexes), 11,000 lbs.
Claw (10): 5d−2 impaling. Reach C-2.
Trample (10): 7d crushing.
Traits: Bad Sight (Low Resolution); Chummy; Discriminatory Smell; DR 2 (Tough Skin); Enhanced Move 1 (Ground Speed 10; Costs Fatigue, 1 FP/Second); Long Neck 1; Peripheral Vision; Quadruped; Weak Bite; Wild Animal.
Skills: Survival (Jungle)-12.
Dicraeosaurus sattleri (15,000 lbs.) increases ST and HP to 49 (damage 5d+1 with claw, 5d+2 with trample).
Amargasaurus cazaui (9,000 lbs.) decreases ST and HP to 42 (damage 4d+1 with claw, 4d+2 with trample) and SM to +5 (6 hexes). Treat the neck spikes as Long Spines which do 1d impaling damage, only for the neck location (free attack at skill 6 for anyone in close combat with the neck hexes, automatic hit against those who grapple the neck, see GURPS Basic Set, p. 88).
Diplodocines
Diplodocus and its relatives were all very long and slender. Supersaurus was the largest and also most heavily built. Like the apatosaurs they lived in western Laurasia during the late Jurassic.
Diplodocus carnegii
ST 61;
DX 10;
IQ 2;
HT 10.
HP 61;
Will 10;
Per 10;
FP 10;
Speed 3.00;
Dodge 6;
Move 6.
SM +7 (23 hexes), 28,000 lbs.
Claw (10): 7d−1 impaling. Reach C-3.
Trample (10): 7d crushing.
Traits: Bad Sight (Low Resolution); Chummy; Discriminatory Smell; DR 3 (Tough Skin); Enhanced Move 1 (Ground Speed 12; Costs Fatigue, 1 FP/Second); Long Neck 3; Peripheral Vision; Quadruped; Weak Bite; Wild Animal.
Skills: Survival (Plains)-12.
This profile is also suitable for Barosaurus lentus.
Diplodocus hallorum (50,000 lbs.) increases ST and HP to 74 (damage 8d with claw, 8d+1 with trample) and DR to 4.
Supersaurus vivianae (110,000 lbs.) increases ST and HP to 96 (damage 10d+1 with claw, 10d+2 with trample) and DR to 4.
Rebbachisaurines
This was the last surviving branch of the diplodocoids. Their ‘primitive’ anatomy indicates they branched off from the others early on, but they are only known from the early Cretaceous. Rebbachisaurus garasbae, Nigersaurus, and Tatouinea were from northern Gondwana, now North Africa. R. agrioensis and Zapalasaurus were from south-western Gondwana, now South America. Demandasaurus was from an island between Gondwana and Laurasia, now Spain.
Rebbachisaurus garasbae
ST 51;
DX 9;
IQ 2;
HT 11.
HP 51;
Will 10;
Per 10;
FP 11;
Speed 3.00;
Dodge 6;
Move 4.
SM +6 (8 hexes), 17,000 lbs.
Claw (9): 6d−2 impaling. Reach C-2.
Trample (9): 6d−1 crushing.
Traits: Bad Sight (Low Resolution); Chummy; Discriminatory Smell; DR 3 (Tough Skin); Enhanced Move 1 (Ground Speed 8; Costs Fatigue, 1 FP/Second); Long Neck 2; Peripheral Vision; Quadruped; Weak Bite; Wild Animal.
Skills: Survival (Swampland)-12.
This profile also suits Rebbachisaurus tessonai and Tatouinea hannibalis.
R. agrioensis, Demandasaurus darwini, Nigersaurus taqueti, and Zapalasaurus bonapartei (5,000 lbs.) reduce ST and HP to 34 (damage 3d+1 with claw, 3d+2 with trample), SM to +4 (5 hexes), and DR to 2.
