Reviewing, Revising, and Finalizing Prehistoric Animals and Dinosaur Ecology

Building a Better Stegosaurus

Stegosaurs
Stegosaurs lived from the Mid Jurassic to Early Cretaceous (175-100 MYA)

Stegosaurus
Late Jurassic (150-145 MYA)
Huge Animal
Hit Dice: 13d8+78 (136 hp)
Initiative: +3
Speed: 20 ft. (4 squares)
Armor Class: 18 (–2 size, –1 Dex, +11 natural), touch 7, flat-footed 18
Base Attack/Grapple: +9/+25
Attack: Tail-spikes +16 melee (3d8+12/×3) or offensive armour +15 melee (2d6+8)
Full Attack: Tail-spikes +16 melee (3d8+12/×3) and offensive armour +10 melee (2d6+4)
Space/Reach: 15 ft./10 ft. (15 ft. with tail-spikes)
Special Attacks: Offensive armour 2d6+12, thagomizer
Special Qualities: Damage reduction 6/–, fortification, low-light vision, scent
Saves: Fort +14, Ref +7, Will +5
Abilities: Str 26, Dex 9, Con 23, Int 1, Wis 12, Cha 6
Skills: Listen +11, Spot +11
Feats: Alertness, Endurance, Improved Initiative, Power Attack, Weapon Focus (tail-spikes)
Environment: Temperate or warm plains and forests
Organization: Solitary, pair or herd (3-6)
Challenge Rating: 7
Treasure: None
Alignment: Always neutral
Advancement: 14–20 HD (Huge); 21–39 HD (Gargantuan)
Level Adjustment: —

A Stegosaurus has a bulky body, a powerful tail tipped with 4 formidable spikes and small, narrow head with a tortoise-like beak. A double row of triangular plates runs the length of its back. The tail is thick and powerful, taking up almost half the animal's body length, so the dinosaur's huge hind legs are set near the middle of the animal. Its front legs are sturdy but much shorter than the hind legs, so its head is normally held low to the ground.

These dinosaurs are solitary herbivores, usually only congregating to breed. They can graze on low vegetation or rear up to browse on taller plants. A Stegosaurus's centre of balance is near its massive hind legs, which allows it to rear up onto a tripod formed from its hind legs and tail to reach tall vegetation or get a better sense of its surroundings. It can also turn around with surprising alacrity by pushing sideways with its forelegs.

A Stegosaurus has excellent defences. Its thick skin provides good armour, and is reinforced with bony ossicles over its throat and flanks, fortifying those vulnerable areas from attack. The large plates along its back are too thin to be effective armour. The cluster of four spikes at the tip of its tail is a lethally effective weapon called a Thagomizer, named after the late Neanderthal zoologist-adventurer Thag Simmons,.

A full grown Stegosaurus is between 25 and 30 feet long from nose to tail-tip, and weighs from 5,000 to 10,000 pounds. Extremely large individuals can approach a Gargantuan 40 feet in length. A typical 25-30 foot long Stegosaurus is 11-13½ tall, including 2-2½ feet of height from its largest dorsal plates, with the actual back standing 9-11 feet above the ground. The spikes on their thagomizer can exceed a yard in length.

Combat
A Stegosaurus will pugnaciously defend itself from threats, responding surprisingly promptly for such a bulky animal. They attack with body-slams and swings of their tail-spikes, and can use the plates and spikes of their armour to cut and stab at any creature grappling with them.

Damage Reduction (Ex): A Stegosaurus has a Damage Reduction equal to half its Hit Dice.

Fortification (Ex): Whenever a critical hit or sneak attack is scored on a Stegosaurus there is a 50% chance that the special attack is negated and its damage is rolled normally.

Offensive Armour (Ex): A Stegosaurus can use its spikes, plates and body-slams to do 2d6+12 crushing, slashing and piercing damage on a successful grapple attack. They can also use their armour to make standard or secondary melee attacks.

Thagomizer (Ex): A Stegosaurus's tail-spikes attack is treated as a 2-handed weapon, so it gains 1½ times the creatures Strength bonus and the Power Attack feat adds +2 damage per –1 attack penalty. The thagomizer inflicts piercing damage, has a reach equal to a tall creature of the Stegosaurus's size, and does ×3 damage on a confirmed critical.

Gargantuan Stegosaurus
Gargantuan Animal
Hit Dice: 21d8+168 (262 hp)
Initiative: +3
Speed: 20 ft. (4 squares)
Armor Class: 20 (–4 size, –1 Dex, +15 natural), touch 5, flat-footed 20
Base Attack/Grapple: +15/+39
Attack: Tail-spikes +24 melee (4d8+18/19-20×3) or offensive armour +23 melee (3d6+12)
Full Attack: Tail-spikes +24 melee (4d8+18/19-20×3) and offensive armour +18 melee (3d6+6)
Space/Reach: 20 ft./15 ft. (20 ft. with tail-spikes)
Special Attacks: Offensive armour 3d6+18, thagomizer
Special Qualities: Damage reduction 10/–, fortification, low-light vision, scent
Saves: Fort +20, Ref +15, Will +10
Abilities: Str 34, Dex 9, Con 27, Int 1, Wis 12, Cha 6
Skills: Listen +15, Spot +15
Feats: Alertness, Endurance, Improved Critical (tail-spikes), Improved Initiative, Iron Will, Power Attack, Weapon Focus (tail-spikes)
Epic Feat: Epic Reflexes
Environment: Temperate or warm plains and forests
Organization: Solitary, pair or herd (3-6)
Challenge Rating: 10
Treasure: None
Alignment: Always neutral
Advancement: 22–39 HD (Gargantuan)
Level Adjustment: —

A Stegosaurus of truly extraordinarily size, 40 feet in length and weighing 25000 pounds or more.

It's possible these dinosaurs never reached such spectacular dimensions in real life.

Other Stegosaurs
The genus Stegosaurus includes the largest known species of Stegosaur although Dacentrurus armatus may rival it in size. Some of the other Stegosaurs are a bit smaller than Stegosaurus but still Huge-sized, for example Tuojiangosaurus multispinus. The smaller species are Large-sized, such as Chungkingosaurus (10-12 feet long) or Kentrosaurus aethiopicus (12-15 feet long).

Most Stegosaurs do not have dorsal plates as large and broad as Stegosaurus. Many genera, like Tuojiangosaurus, have pointier dorsal plates that become more spike-shaped as they get closer to their tail, the change in shape is quite dramatic in such Stegosaurs as Dacentrurus or Kentrosaurus , whose dorsal armour abruptly switches from plates to spikes above the animal's hips. Some Stegosaurs, such as Chungkingosaurus or the aforementioned Kentrosaurus have an additional large spike upon each shoulderor, in the case of Huayangosaurus, above each hip. It is possible other Stegosaurs had these additional shoulder- or hip-spikes, and they haven't been found in the fossil record, or have just not been identified yet.

The 'spikier' Stegosaurs' more bellicose dorsal plates may be enough to give them slightly higher damage, a +2 or +4 racial bonus on grapple checks when attacking with their Offensive Armour, or the Spiny Defence quality (see Chungkingosaurus for details).

Tuojiangosaurus
Late Jurassic (160-155 MYA)
Huge Animal
Hit Dice: 11d8+66 (115 hp)
Initiative: +3
Speed: 20 ft. (4 squares)
Armor Class: 18 (–2 size, –1 Dex, +11 natural), touch 7, flat-footed 18
Base Attack/Grapple: +8/+23
Attack: Tail-spikes +14 melee (3d8+10/×3) or offensive armour +13 melee (2d6+7)
Full Attack: Tail-spikes +14 melee (3d8+10/×3) and offensive armour +8 melee (2d6+3)
Space/Reach: 15 ft./10 ft. (15 ft. with tail-spikes)
Special Attacks: Offensive armour 2d6+10, thagomizer
Special Qualities: Damage reduction 5/–, fortification, low-light vision, scent
Saves: Fort +13, Ref +6, Will +4
Abilities: Str 24, Dex 9, Con 23, Int 1, Wis 12, Cha 6
Skills: Listen +10, Spot +10
Feats: Alertness, Endurance, Improved Initiative, Weapon Focus (tail-spikes)
Environment: Temperate or warm plains and forests
Organization: Solitary, pair or herd (3-6)
Challenge Rating: 6
Treasure: None
Alignment: Always neutral
Advancement: 12–20 HD (Huge); 21–33 HD (Gargantuan)
Level Adjustment: —

Typical of a medium to big sized Stegosaur. Huge in size, but not as enormous as Stegosaurus proper.

An average Tuojiangosaurus is around 20 to 25 feet long and weighs between 4000 and 5000 pounds.

Chungkingosaurus
Late Jurassic (160-145 MYA)
Large Animal
Hit Dice: 6d8+24 (51 hp)
Initiative: +4
Speed: 20 ft. (4 squares)
Armor Class: 17 (–1 size, +8 natural), touch 9, flat-footed 17
Base Attack/Grapple: +4/+12 [+16 with Offensive Armour]
Attack: Tail-spikes +8 melee (2d8+6/×3) or offensive armour +7 melee (1d10+4)
Full Attack: Tail-spikes +8 melee (2d8+6/×3) and offensive armour +2 melee (1d10+2)
Space/Reach: 10 ft./5 ft. (10 ft. with tail-spikes)
Special Attacks: Offensive armour 1d10+6, thagomizer
Special Qualities: Damage reduction 3/–, fortification, low-light vision, scent, spiny defence 1d10+4
Saves: Fort +9, Ref +5, Will +3
Abilities: Str 18, Dex 11, Con 19, Int 1, Wis 12, Cha 6
Skills: Listen +8, Spot +7
Feats: Alertness, Improved Initiative, Weapon Focus (tail-spikes)
Environment: Temperate or warm plains and forests
Organization: Solitary, pair or herd (3-6)
Challenge Rating: 3
Treasure: None
Alignment: Always neutral
Advancement: 7–10 HD (Large); 11–18 HD (Huge)
Level Adjustment: —

One of the smallest of Stegosaurs, these dinosaurs have an abundance of armour spines which give them a +4 racial bonus on the Offensive Armour grapple checks and increases the armour's damage to 1d10.

An adult Chungkingosaurus is typically between 10 and 13 feet long and weighs over 500 pounds.

Combat

Damage Reduction (Ex): A Chungkingosaurus has a Damage Reduction equal to half its Hit Dice.

Fortification (Ex): Whenever a critical hit or sneak attack is scored on a Chungkingosaurus there is a 50% chance that the special attack is negated and its damage is rolled normally.

Offensive Armour (Ex): A Chungkingosaurus can use its spikes, plates and body-slams to do 1d10+6 crushing, slashing and piercing damage on a successful grapple attack with a +4 racial bonus on this check. They can also use their armour to make standard or secondary melee attacks.

Thagomizer (Ex): A Chungkingosaurus's tail-spikes attack is treated as a 2-handed weapon, so it gains 1½ times the creatures Strength bonus and the Power Attack feat adds +2 damage per –1 attack penalty. The thagomizer inflicts piercing damage, has a reach equal to a tall creature of the Chungkingosaurus's size, and does ×3 damage on a confirmed critical.

Spiny Defence (Ex): Any creature that hits a Chungkingosaurus in melee using a handheld or natural weapon (but not a reach weapon) must succeed on a DC 13 Reflex save or take 1d10+4 points of damage from one of the creature’s spikes or dorsal spines. The save DC is Dexterity-based.

Building a Better Ankylosaurus

Ankylosaurs and their Kin
Various types of Ankylosaur lived from the Late Jurassic to the Late Cretaceous (155-65 MYA)
True Anklosauridae with tail-clubs probably didn't emerge until the Early Cretaceous (125 MYA)

Ankylosaurus
Late Cretaceous (70-65 MYA)
Huge Animal
Hit Dice: 11d8+77 (126 hp)
Initiative: –2
Speed: 15 ft. (3 squares)
Armor Class: 18 (–2 size, –2 Dex, +12 natural), touch 6, flat-footed 18
Base Attack/Grapple: +7/+22
Attack: Tail-club +13 melee (3d8+10/19-20)
Full Attack: Tail-club +13 melee (3d8+10/19-20) and slam +7 melee (2d6+3)
Space/Reach: 15 ft./10 ft. (15 ft. with tail-club)
Special Attacks: Tail-club
Special Qualities: Damage reduction 12/–, low-light vision, scent, total fortification, weapon-breaking armour
Saves: Fort +14, Ref +5, Will +4
Abilities: Str 25, Dex 7, Con 24, Int 1, Wis 12, Cha 4
Skills: Listen +10, Spot +10
Feats: Alertness, Awesome Blow (B), Endurance, Power Attack, Weapon Focus (tail-club)
Environment: Temperate or warm plains and forests
Organization: Solitary, pair or herd (3-6)
Challenge Rating: 6
Treasure: None
Alignment: Always neutral
Advancement: 12–20 HD (Huge); 21–39 HD (Gargantuan)
Level Adjustment: —

An Ankylosaurus has a broad, low-slung body covered in bony protrusions, four short and thick legs, a small blocky head with a tortoise-like beak and a powerful tail ending in a double-lobed bony club. Every part of its body is covered by armour, even its eyes have bony lids.

These dinosaurs are solitary herbivores, usually only congregating to breed. They are resilient animals able to live in harsh conditions, some species lived in saline wastelands and deserts.

The above stats are for a modest sized Ankylosaurus between 15 and 25 feet from beak to tail-club, such a creature could weigh between 4000 and 16000 pounds. The same stats can be used for other large genera of Ankylosauridae such as Euoplocephalus, Saichania or Tarchia.

Combat
Ankylosaurus usually only attacks if closely approached by an apparent threat. It relies on its formidable armour and smashing tail-club in combat, hunkering down and lashing out until its opponents either give up or manage to break through its armour. They do not flee from attackers, because they're simply too slow to outrun any of the prehistoric predators they're likely to meet.

Damage Reduction (Ex): A standard Ankylosaurus has a Damage Reduction equal to 7 plus half its Hit Dice. A Medium-sized Ankylosaurus has a DR of 2 plus its Hit Dice, A Large-sized Ankylosaurus has a DR of 5 plus half its Hit Dice, a Gargantuan one has a DR of 8 plus half its Hit Dice.

Tail Club (Ex): An Ankylosaurus's tail-club attack is treated as a 2-handed weapon, so it gains 1½ times the creatures Strength bonus and the Power Attack feat adds +2 damage per –1 attack penalty. The tail-club inflicts crushing damage, has a reach equal to a tall creature of the Ankylosaurus's size, and threatens a critical on a 19-20.

Total Fortification (Ex): Ankylosaurus takes normal damage from critical hits or sneak attacks. Its bony armour shields every vital organ, negating such special attacks.

Weapon-Breaking Armour (Ex): An Ankylosaurus's armour is so thick, rough and hard that it can damage weapons that strike it. Any weapon that hits the dinosaur takes 1d10+7 points of damage unless the attacker succeeds at a DC 21 Reflex save. The damage the weapon takes can not exceed the damage it rolled against the Ankylosaurus. If a natural weapon hits the Ankylosaurus, the attacking creature takes the indicated damage. Weapons that are objects, such as most handheld and missile weapons, take half damage as per the standard rules. The save DC is Constitution-based.

Big Ankylosaurus
Huge Animal
Hit Dice: 16d8+126 (200 hp)
Initiative: –2
Speed: 15 ft. (3 squares)
Armor Class: 20 (–2 size, –2 Dex, +14 natural), touch 6, flat-footed 20
Base Attack/Grapple: +12/+29
Attack: Tail-club +20 melee (3d8+13/17-20) or slam +19 melee (2d6+9)
Full Attack: Tail-club +20 melee (3d8+13/17-20) and slam +14 melee (2d6+4)
Space/Reach: 15 ft./10 ft. (15 ft. with tail-club)
Special Attacks: Tail-club
Special Qualities: Damage reduction 15/–, low-light vision, scent, total fortification, weapon-breaking armour [DC25, 1d10+9]
Saves: Fort +18, Ref +8, Will +6
Abilities: Str 29, Dex 7, Con 26, Int 1, Wis 12, Cha 4
Skills: Listen +10, Spot +10
Feats: Ability Focus (weapon-breaking armour), Alertness, Awesome Blow (B), Endurance, Improved Critical (tail-club), Power Attack, Weapon Focus (tail-club)
Environment: Temperate or warm plains and forests
Organization: Solitary, pair or herd (3-6)
Challenge Rating: 8
Treasure: None
Alignment: Always neutral
Advancement: 17–20 HD (Huge); 21–39 HD (Gargantuan)
Level Adjustment: —

The above represents an Ankylosaurus magniventris or similar species of Ankylosaur at the upper limit of its size.

25-30 feet long, 16000-32000 pounds.

Gargantuan Ankylosaurus
Gargantuan Animal
Hit Dice: 21d8+189 (283 hp)
Initiative: –2
Speed: 15 ft. (3 squares)
Armor Class: 21 (–4 size, –2 Dex, +17 natural), touch 4, flat-footed 21
Base Attack/Grapple: +15/+38
Attack: Tail-club +23 melee (5d8+16/17-20) or slam +22 melee (3d6+11)
Full Attack: Tail-club +23 melee (5d8+16/17-20) and slam +17 melee (3d6+5)
Space/Reach: 20 ft./15 ft. (20 ft. with tail-club)
Special Attacks: Tail-club
Special Qualities: Damage reduction 18/–, low-light vision, scent, total fortification, weapon-breaking armour [DC28, 2d8+11]
Saves: Fort +21, Ref +9, Will +8
Abilities: Str 33, Dex 5, Con 28, Int 1, Wis 12, Cha 4
Skills: Listen +15, Spot +15
Feats: Ability Focus (weapon-breaking armour), Alertness, Awesome Blow (B), Endurance, Improved Critical (tail-club), Improved Natural Attack (tail-club), Power Attack, Weapon Focus (tail-club)
Epic Feat: Armour Skin
Environment: Temperate or warm plains and forests
Organization: Solitary, pair or herd (3-6)
Challenge Rating: 10
Treasure: None
Alignment: Always neutral
Advancement: 22–39 HD (Gargantuan)
Level Adjustment: —

An implausibly large Ankylosaur, over 30 feet long and weighing 16 tons or more.

Other Ankylosaurs
Many Ankylosaurs are fairly large, about 20 feet or so, and use the "standard Ankylosaurus" stats given above. There are smaller varieties, such as the following:

Tianzhenosaurus (Lesser Ankylosaur)
Late Cretaceous (85-70 MYA)
Large Animal
Hit Dice: 6d8+30 (57 hp)
Initiative: –2
Speed: 15 ft. (3 squares)
Armor Class: 17 (–1 size, –2 Dex, +10 natural), touch 7, flat-footed 17
Base Attack/Grapple: +4/+13
Attack: Tail-club +9 melee (2d8+7/19-20)
Full Attack: Tail-club +9 melee (2d8+7/19-20) and slam +3 melee (1d8+3)
Space/Reach: 10 ft./5 ft. (10 ft. with tail-club)
Special Attacks: Tail-club
Special Qualities: Damage reduction 8/–, low-light vision, scent, total fortification, weapon-breaking armour [DC18, 1d8+5]
Saves: Fort +10, Ref +3, Will +3
Abilities: Str 21, Dex 7, Con 20, Int 1, Wis 12, Cha 4
Skills: Listen +8, Spot +7
Feats: Alertness, Awesome Blow (B), Endurance, Weapon Focus (tail-club)
Environment: Temperate or warm plains and forests
Organization: Solitary, pair or herd (3-6)
Challenge Rating: 4
Treasure: None
Alignment: Always neutral
Advancement: 7–10 HD (Large); 11–15 HD (Huge)
Level Adjustment: —

A typical example of a smaller variety of Ankylosaur, these stats can also be used for such modest sized armoured dinosaurs including immature or undersized examples or larger species. (Indeed, it has been proposed that Tianzhenosaurus youngi itself are just small specimens of the 20+ foot long Saichania chulsanensis)

Tianzhenosaurus are between 10 and 15 feet long and weigh around 2000 pounds.

Minmi (Pygmy Ankylosaur)
Early Cretaceous (120-115 MYA)
Medium Animal
Hit Dice: 3d8+12 (25 hp)
Initiative: –1
Speed: 15 ft. (3 squares)
Armor Class: 17 (–1 Dex, +8 natural), touch 9, flat-footed 17
Base Attack/Grapple: +2/+5
Attack: Tail-club +5 melee (1d10+4/19-20)
Full Attack: Tail-club +5 melee (1d10+4/19-20) and slam +0 melee (1d6+1)
Space/Reach: 5 ft./5 ft.
Special Attacks: Tail-club
Special Qualities: Damage reduction 5/–, low-light vision, scent, total fortification, weapon-breaking armour [DC15, 1d6+3]
Saves: Fort +7, Ref +2, Will +2
Abilities: Str 17, Dex 9, Con 18, Int 1, Wis 12, Cha 4
Skills: Listen +6, Spot +6
Feats: Alertness, Endurance
Environment: Temperate or warm plains and forests
Organization: Solitary, pair or herd (3-6)
Challenge Rating: 2
Treasure: None
Alignment: Always neutral
Advancement: 4–5 HD (Medium); 6–9 HD (Large)
Level Adjustment: —

Minmi is a comparatively miniscule armoured dinosaur that may be an ancestor of both true Ankylosaurs and Nodosaurs. It probably did not have a full tail-club, but is statted here as if it did. These stats can be used to represent Minmi paravertebra itself, as well as youngsters of larger species and pygmy Ankylosaurs.

Minmi is only 6-7 feet long but weighs 300-400 pounds.

Nodosaurs
Nodosaurs are close relatives of Ankylosaurs. The main difference as far as their D&D stats are concerned is they do not have a club on the end of their tail, although that member is still reinforced for striking opponents.

Use the stats for Ankylosaurs, except their tail-club SA is replaced by a tail-rod SA that lacks the improved critical threat range, although it still has the 2-handed Strength bonus.

Polacanthids
These are primitive forms of armoured dinosaur, their armour is not as well developed as an Ankylosaur or Nodosaur, and they lack a tail-club. They are do not grow as large as their younger kin: Polecanthus itself is 13-16 feet long, and even the largest genera such as Hylaeosaurus may not have exceeded 20 feet in total length.

Gargoyleosaurus
Late Jurassic (155-145 MYA)
Large Animal
Hit Dice: 6d8+30 (57 hp)
Initiative: –1
Speed: 20 ft. (4 squares)
Armor Class: 16 (–1 size, –1 Dex, +8 natural), touch 8, flat-footed 16
Base Attack/Grapple: +4/+13
Attack: Tail-slap +9 melee (2d6+7)
Full Attack: Tail-slap +9 melee (2d6+7) and slam +3 melee (1d8+3)
Space/Reach: 10 ft./5 ft. (10 ft. with tail-slap)
Special Attacks: —
Special Qualities: Damage reduction 4/–, low-light vision, scent, heavy fortification, weapon-breaking armour
Saves: Fort +10, Ref +4, Will +3
Abilities: Str 21, Dex 9, Con 20, Int 1, Wis 12, Cha 4
Skills: Listen +8, Spot +7
Feats: Alertness, Awesome Blow (B), Endurance, Weapon Focus (tail-slap)
Environment: Temperate or warm plains and forests
Organization: Solitary, pair or herd (3-6)
Challenge Rating: 3
Treasure: None
Alignment: Always neutral
Advancement: 7–10 HD (Large); 11–15 HD (Huge)
Level Adjustment: —

Gargoyleosaurus parkpinorum is one of the smaller species of Polecanthids. A typical adult is between 10 and 13 feet long from beak to tail-tip and could weigh between 1000 and 2000 pounds.

Combat
Gargoyleosaurus usually only attacks if closely approached by an apparent threat. It relies on its formidable armour and powerful tail-slaps in combat, hunkering down and lashing out until its opponents either give up or manage to break through its armour. They do not flee from attackers, because they're simply too slow to outrun any of the prehistoric predators they're likely to meet.

Damage Reduction (Ex): A standard Gargoyleosaurus has a Damage Reduction equal to 2 plus 1 for every third Hit Dice. A Huge-sized Gargoyleosaurus has a DR of 3 plus a third its Hit Dice.

Heavy Fortification (Ex): A Gargoyleosaurus's bony armour covers most of its vital organs. If it is struck by a critical hit or sneak attack it has a 75% chance of taking normal damage.

Weapon-Breaking Armour (Ex): A Gargoyleosaurus's armour is so thick, rough and hard that it can damage weapons that strike it. Any weapon that hits the dinosaur takes 1d6+5 points of damage unless the attacker succeeds at a DC 18 Reflex save. The damage the weapon takes can not exceed the damage it rolled against the Gargoyleosaurus. If a natural weapon hits the Gargoyleosaurus, the attacking creature takes the indicated damage. Weapons that are objects, such as most handheld and missile weapons, take half damage as per the standard rules. The save DC is Constitution-based.

Gastonia
Early Cretaceous (125 MYA)
Large Animal
Hit Dice: 6d8+30 (57 hp)
Initiative: –2
Speed: 15 ft. (3 squares)
Armor Class: 16 (–1 size, –2 Dex, +9 natural), touch 8, flat-footed 16
Base Attack/Grapple: +4/+13 [+17 with offensive armour]
Attack: Tail-shears +9 melee (2d6+7/19-20) or offensive armour +8 melee (1d10+5)
Full Attack: Tail-shears +9 melee (2d6+7/19-20) and offensive armour +3 melee (1d10+3)
Space/Reach: 10 ft./5 ft. (10 feet with tail-shears)
Special Attacks: Offensive armour, tail-shears
Special Qualities: Damage reduction 8/–, low-light vision, scent, heavy fortification, weapon-breaking armour
Saves: Fort +10, Ref +3, Will +3
Abilities: Str 21, Dex 7, Con 20, Int 1, Wis 12, Cha 4
Skills: Listen +8, Spot +7
Feats: Alertness, Awesome Blow (B), Endurance, Weapon Focus (tail-shears)
Environment: Temperate or warm plains and forests
Organization: Solitary, pair or herd (3-6)
Challenge Rating: 4
Treasure: None
Alignment: Always neutral
Advancement: 7–10 HD (Large); 11–15 HD (Huge)
Level Adjustment: —

A low-slung and enormously broad animal covered in thick bony armour, with a small box-shaped skull and a thick tail. It is covered with sharp looking horn-plated spikes - two rows of spines on its back shaped like giant rose thorns, and a row of thick triangular blades running down each flank from its shoulder to the end of its powerful tail.

Gastonia is a small to medium Polecanthid dinosaur with exceptionally well developed armour and weaponry. Some of the triangular plates that edge its tail are positioned to slide over each other when the tail bends, acting like a row of foot-long scissor blades made of sharpened bone. The head, throat and the back of its body and tail are plated with thick armour, including a massive shield of bone over the hips. Its legs and underside are comparatively lightly armoured.

A typical adult Gastonia is about 13 feet long from beak to tail-tip and weighs roughly 2000 pounds.

Combat
Gastonia usually only attacks if closely approached by an apparent threat. It relies on its formidable armour and powerful tail-slaps in combat, hunkering down and lashing out until its opponents either give up or manage to break through its armour. They do not flee from attackers, because they're simply too slow to outrun any of the prehistoric predators they're likely to meet.

Damage Reduction (Ex): A Large Gastonia has a Damage Reduction equal to 5 plus half its Hit Dice. A Huge Gastonia has a DR of 7 plus half its Hit Dice.

Heavy Fortification (Ex): A Gastonia's bony armour covers most of its vital organs. If it is struck by a critical hit or sneak attack it has a 75% chance of taking normal damage.

Offensive Armour (Ex): A Gastonia can use its spikes, plates and body-slams to do 1d10+5 crushing, slashing and piercing damage on a successful grapple attack with a +4 racial bonus on this check. They can also use their armour to make standard or secondary melee attacks.

Tail-Shears (Ex): A Gastonia's tail-shears attack is treated as a 2-handed weapon, so it gains 1½ times the creatures Strength bonus and the Power Attack feat adds +2 damage per –1 attack penalty. The tail-shears inflicts crushing and slashing damage, has a reach equal to a tall creature of the Gastonia's size, and threatens a critical on a 19-20.

Weapon-Breaking Armour (Ex): A Gastonia's armour is so thick, rough and hard that it can damage weapons that strike it. Any weapon that hits the dinosaur takes 1d6+5 points of damage unless the attacker succeeds at a DC 18 Reflex save. The damage the weapon takes can not exceed the damage it rolled against the Gastonia. If a natural weapon hits the Gastonia, the attacking creature takes the indicated damage. Weapons that are objects, such as most handheld and missile weapons, take half damage as per the standard rules. The save DC is Constitution-based.

The above Ankylosaurus entry is not quite finished. I've just watched the part of Jurassic Fight Club with its rather sensationalised interpretion of Gastonia (the "chainsaw-tailed porcupine built like a Sherman tank" one), so I plan on doing stats for it.

Shouldn't take me long.

Pathfinder statblocks

While I am a little wary, there are some things I think they definitely got right.

First- that creatures with a sufficiently long appendage (tail, in the case of the Tarrasque, neck, in the case of Elasmosaurus) can break the normal reach rules.

Elasmosaurus has a 15 ft space, and a 20 ft Reach

the Tarrasque, has a 30 ft space, and a 60 ft tail slap reach.

Second- that large sauropods, such as Brachiosaurus, are Gargantuan, rather than Colossal.

Combining the two- we could get:

a Diplodocus- which is Gargantuan, 20 ft Space, 40 ft Tail Slap reach.

Does this sound like an improvement on the Dragon Magazine 318 Diplodocus- which is Colossal, 30 ft Space, 20 ft Reach with tail slap, and has a 40 ft half-circle Tail Sweep special attack?

Also- the ankylosaur and stegosaur stats look good.

hamishspence said:

While I am a little wary, there are some things I think they definitely got right.

First- that creatures with a sufficiently long appendage (tail, in the case of the Tarrasque, neck, in the case of Elasmosaurus) can break the normal reach rules.

Elasmosaurus has a 15 ft space, and a 20 ft Reach

the Tarrasque, has a 30 ft space, and a 60 ft tail slap reach.

Second- that large sauropods, such as Brachiosaurus, are Gargantuan, rather than Colossal.

Combining the two- we could get:

a Diplodocus- which is Gargantuan, 20 ft Space, 40 ft Tail Slap reach.

Does this sound like an improvement on the Dragon Magazine 318 Diplodocus- which is Colossal, 30 ft Space, 20 ft Reach with tail slap, and has a 40 ft half-circle Tail Sweep special attack?

Also- the ankylosaur and stegosaur stats look good.

Click to expand...

I agree. There's plenty of precedent for extra-reach natural attacks, so I felt no qualms about using it in my own version of Elasmosaurus and the Sauropods.

Speaking of Sauropoda, I really need to add separate stats for the bipedal Prosauropoda, the 'lesser Sauropods' don't represent them very well, the stats were really meant for juvenile sauropods and their quadrupedal ancestors.

sizes

Aside from preferring Gargantuan to Huge for Diplodocus itself, I like the stats- and a slightly smaller diplodocid can probably fill the Huge slot.

Depending on how accurate Ken Carpenter's reconstruction of Amphicoelias fragillimus is, it could have a Space and reach of anywhere between 30 ft space 60 ft reach, to 50 ft Space, 100 ft reach.

It probably works as the biggest diplodocid, with Supersaurus maybe being the next biggest.

The high figures are (still somewhat speculative) 55 ft neck, 30 ft body, 105 ft tail.

Set slightly toward the back of a 50 ft base (forelegs 15 ft from the front edge, rear legs 5 ft from the rear edge) the result is a neck extending roughly 40 ft forward, and a tail extending 100 ft rearward.

which works out quite well with 50 ft Space, 100 ft Tail Slap Reach.

This is, however, the maximum estimated size- based solely on drawings of one vertabra.

Upon reflection, I realized I've rather mucked up the 'Short-Faced' Carnosaurs entry. I've been reading about Majungasaurus recently and that warped my conception of Abelisaurs. If I'd actually thought a moment I'd remember that most of the large Abelisaurs (e.g. Abelisaurus, Aucasaurus, Carnotaurus, Rugops et al) have pretty long, slim legs to go with a big but fairly lightweight heads and wee little arms.

I'd better split them into a gracile version called the 'Short Faced Carnosaur' and a heavyweight version for Majungasaurus and its ilk (Maybe Rajasaurus?) we can call something like "Pit Bull Carnosaurs".

We could probably get away with just modifying the Classic Carnosaur or the Gracile Tyrant, but I'd rather give them their own stat-category. They won't have the claw attacks of regular Allosauroid carnosaurs, and their jaws may be more suited for grappling large prey as compared to Allosaurs slashing teeth. They don't have a Tyrannosaurs' crushing bite strength or larger brains, suggesting lower Int and Wis in D&D terms.

Here's my new, improved theropod stat category list:

Standard Carnosaurs (e.g. Allosaurus) - largish, fairly fast, slashing bite, medium-sized claws. Includes other Allosauridae up to the size of Giganotosaurus. We could probably lump Ceratosaurs in here as far as their stats go.
Gracile Carnosaurs (e.g. Dilophosaurus) - slim, fast, smallish head, medium-small claws.
Clawed Carnosaurs (e.g. Megaraptor) - Carnivorous theropods with unusually large arms & claws and smallish heads with slashing teeth. Swift and gracile, may have chased down agile prey.
Crocodile Carnosaurs (e.g. Spinosaurus) Largish arms and claws. Slim jaws with pointed teeth for wriggling prey. may be piscovores. Baryonyx may be a robust version.
Short-Faced Carnosaurs (e.g. Abelisaurus) - long legs and tiny arms, short but deep skull. [Modified Gracile Tyrant?]
Pit-Bull Carnosaurs (e.g. Majungasaurus) - Powerful but slow, with short sturdy legs. Deep skull and stubby teeth may have allowed pit-bull like wrestling with larger prey animals. [Modified Tyrant King?]
Tyrant Kings (e.g. Tyrannosaurus) - large & strong, bigger brains, powerful crushing & tearing bite, tiny claws.
Gracile Tyrants (e.g. Albertosaurus) - faster than the above, with less powerful jaws.
'Raptors' (e.g. Deinonychus) - fast & agile, well armed with claws, talons & teeth. [Maybe call them Terror Claws?]
Gracile Raptors (e.g. Troodon) - slimmer and faster than above, but not as strong.
Short-Armed Raptors (e.g. Austroraptor). Unusually small arms and slim jaws. Maybe particularly fast pursuers of small prey?
Flapping Raptors (e.g. Unenlagia, Microraptor). Very small, with wings or winglike forearms. Some may have had limited flight, maybe good climbers that lived on trees or cliffs.
Beaked Raptors (e.g. Oviraptor) - small, fast, medium claws, beaked. Maybe omnivores. [I decided to drop 'Oviraptor' since calling them 'egg thieves' would give the wrong impression of their habits]
Scythe Claws (e.g. Therizinosaurus) - bizarre barrel-bodied theropods with huge claws. Probably herbivores.
Ostrich Mimics (e.g. Ornithomimus) - fast, with long 3-clawed arms but a negligible peck. Maybe omnivores.

hamishspence said:

Aside from preferring Gargantuan to Huge for Diplodocus itself, I like the stats- and a slightly smaller diplodocid can probably fill the Huge slot.

Click to expand...

I decided to start all the "Greater Sauropods" at Huge just for consistency, to allow for the relatively small species and immature versions of the adults.

In the case of Diplodocus, it was a remarkably long and lightly built animal, and many of its recent weight estimates put it around 10-16 tons, so I felt safe making it Huge. I was a lot more queasy about not statting the base Apatosaurus as Huge - adults of that animal should pretty definitely be Gargantuan.

hamishspence said:

Depending on how accurate Ken Carpenter's reconstruction of Amphicoelias fragillimus is, it could have a Space and reach of anywhere between 30 ft space 60 ft reach, to 50 ft Space, 100 ft reach.

It probably works as the biggest diplodocid, with Supersaurus maybe being the next biggest.

The high figures are (still somewhat speculative) 55 ft neck, 30 ft body, 105 ft tail.

Set slightly toward the back of a 50 ft base (forelegs 15 ft from the front edge, rear legs 5 ft from the rear edge) the result is a neck extending roughly 40 ft forward, and a tail extending 100 ft rearward.

which works out quite well with 50 ft Space, 100 ft Tail Slap Reach.

This is, however, the maximum estimated size- based solely on drawings of one vertabra.

Click to expand...

I think Supersized Diplodocids are adequately covered by my proposed stats without having to invent a new size bigger than Colossal, especially as it has practically no evidence for how big it actually was. They give a Colossal Diplodocid with a 30 foot space, a 30 foot neck and a 90 foot tail. I think 150 feet total length is quite enough!

I did consider giving Diplodocids 50% or 100% extra neck reach as well as a 50% longer tail, which would add 15-30 feet to its length (165-180 feet).

Upon reflection, I should really have done so. What do you think of doubling the Diplodocids's bite reach?

3.5 and Colosaal

3.5 statblocks do (sometimes) allow for Colossal creatures with a Space larger than 30 ft.

the 3.5 revision to Epic Handbook, gives the devastation vermin, and the biggest Abomination, a 50 ft space.

Elder Evils gives the advanced Aspect of the Leviathan a 60 ft Space.

But otherwise, they follow the normal Colossal rules.

Remember that the body of the creature, if placed on a Gargantuan or Colossal base, will only take up a fairly small portion- so it's neck reach will be less than its total neck length. Supersaurus and Barosaurus might have slightly extended neck reach.

also- the larger specimens of Diplodocus (Diplodocus hallorum, AKA Seismosaurus), may have weighed a bit more than 16 tons.

The original WoTC thread gives Apatosaurus a Gargantuan size- which is reasonable, given that adults were between 70 and 80 ft long.

One of the things that might cause all the size disputes- is that base size advances slower than height does-
6 ft creature on a 5 ft base is a middle of the height-range Medium biped.
48 ft creature on a 20 ft base is a middle of the height-range Gargantuan biped.

result- it looks cramped.

sauropod size

While base size does not scale well, I figure a 15 ft sauropod body (discounting neck and tail) sitting on a 20 ft base, looks passable.

Diplodocus and Apatosaurus have very similar body sizes- one is just chunkier than the other.

Hence, my idea of Diplodocus being the smallest (in hit dice) of the Gargantuan diplodocids.

Put it on a 15 ft base though- and place it next to other Huge creatures- and it will dwarf them.

For skeletal drawings- with a 1 metre scale bar- which can be used to work out how big the "model's base" should be (6m = roughly 20 ft- Gargantuan base size) see here:

http://www.skeletaldrawing.com/sauropods/sauropods.htm

The artist, who was one of the paleontologists who reconstructed Supersaurus, has a reputation as one of the better dinosaur artists out there.

Weight is important- but some creatures are, being lightly built, a little larger than their weight would suggest.

Young Diplodocus could be easily Huge though.

One of the things that especially mystifies me are the numerous articles (dated around June 2009) that say that thanks to sizing errors- many of the dinosaur weights need to be revised.

http://dinosaurs.suite101.com/article.cfm/dinosaurs_smaller_than_thought

All well and good- but they list Diplodocus as being revised downward from 5500 kg to 4000 kg.

Since when did anyone think it was 5500 kg?

Even the most conservative estimates I have seen, put a minimum of 10 tons- and mostly, the estimates are larger.

People specializing in pneumacity- who stress that most sauropods are much lighter than originally thought- still give estimates of around 12 tons.