The Scaled Ones

In the times when the great beasts walked the world when the planet was warmer across all lands, the scaled ones first appeared. They tamed dinosaurs, created massive monuments, and ruled on every face of Ursu. There were one hundred kingdoms and as time progressed, the first of the mammal races appeared. The serpent races quickly enslave them, but their mastery is soon undone.
When the Dragonfall occurred, the world began to change. The north became cooler, as did many other lands. The great jungles receded, and the dragons ruled the land and sky. In time, the massive empires were in ruin, reduced to rubble, the stones being used to make new temples to new gods and masters. The scaled races retreated to places where they could be safe to lick their wounds and plan. For all the other races, thankfully, most scaled ones have given up worldwide rule and have come to find new niches in the current state of Ursu. Besides, they say, things always change. The next change may lead to their return to power.

Lizardfolk

The most common of the Scaled Ones, lizardfolk control large sections of jungles and swampland all across Ursu. That being said, there is no unified lizardfolk nation. With the exception of the trading city of Xyoatal on the eastern coast of the Southern Lands, most lizardfolk live in tribal communities. While ruins are found from time to time, this indicates that the lizardfolk were once a powerful and advanced civilization. Those days are long past. It is noted that the lizardfolk appear to keep steady numbers, and while nowhere near as plentiful as other species, the lizardfolk do not appear to be fading into history, like other scaled ones.
Lizardfolk are more insular than most of the scaled races. It is rare to see one outside of its tribe. A lone lizardfolk is often an outcast or social rebel. They almost never go north of the Central Sea, no matter the reason for their departure from the tribe. 
Additionally, the lizardfolk are in a state of almost constant war with the Southern Elves. Both groups overlap in the need for resources, even in their means to preferred travel. To see the two groups clash, riding atop titanic dinosaurs, will leave an impression not soon forgotten. The two groups do not trust the other. Any attempt to form a peace between the two groups have always fallen apart shortly after the negotiations are complete. 

Nagah ("Lamias")

Often misidentified as "lamias", the Nagah are males and females that look human or elven from the waist up with long serpentine bodies underneath. Their obvious human-like appearance has been the cause of much debate among those few scholars who know of their existence. Once they had mighty temples in forests the world over, but when the world cooled, they retreated. Those few that are left are often found in island colonies or dormant in one of their temple complexes in some "haunted" woodland.
The Nagah is an intelligent and wise race, but there have been a number of cells of Nagah that have slipped into decadence in remote corners of the world. These are the ones referred to as Lamia. Most Lamia are lost to their revels, but the occasional Lamia feels the pull of their ancient ancestors and seeks out their kin. Sometimes this leads to a pilgrimage southward. Sometimes this leads to just an adventuring Nagah using the time among others to experience a closeness similar to the legendary bond that the Nagah have with each other when gathered together.

The Eyes of Heaven

The Nagah and some of the other scaled races worship the heavens and have for millennia. There has recently been a change in that worship though. There were, at first three worshipped. The Bright Eye (The Sun) and the Pale Eye (The Moon), are each believed to be masks for Anex and Skadi respectively. The Pale Eye has changed to the Pale Eyes, or the Three Eyes Within The Pale. The next astrological body given reverence to is a large red star (a nearby planet) that they for generations referred to as The Sleeping Eye. It is now The Dreaming Eye or The Ruby Eye. Finally, there is a star that has been noticed by astrologers that moves across the night sky, and an orbiting ball of rock believed to be in a perfect location to be stuck halfway between Ursu and the moon. The Nagah call this The Blue Eye, or The Eye That Looks Forward.

Serpentfolk (Asaatthi)

Among the scaled ones, the Asaatthi were the ones most devastated by the Dragon's Invasion. The Asaathi Empire once spread across Southern Lands, far to the East, and around the Inner Sea. In the present day, they are only found in scattered, well-hidden, remote, and isolated locations. Most sites that were once there have been reclaimed by others and built on top of over the years. Many a major city has a formerly serpent-ruled one just underneath.
The Asaatthi are known as master spellcasters and will workers. For many centuries they were the premier casters of any type of magic available. It is said that they have lost more magic than has ever been discovered since the dragons' arrival. For this reason, a number of expeditions have been launched into remote locations backed by one wizard or another to attempt to find lost secrets.
In the modern era, Asaatthi are considered nothing but the villains in bard tales, fanciful entities lost to the past. Should an Asaatthi be found traveling abroad they may be able to pass themselves off as a "type of Lizardfolk", but that won't stop the local mages in the area from attempting to find them and wring out what mysteries they could.
There are rumors of an open conclave of Asaatthi hidden in either the capital of Talvik or the city of Norcastle, but there are many stories about many things that happened in those two locations to be believed.

Vishkanya

Found mostly in the lands to the east, Xang-ji and Vedia, vishkanya have still had a minor presence in the west. Most often found in trade cities, they are considered both alluring and dangerous. They are popular to have in one's employ because of their poisonous natures. Their natural venom is the core to that reputation, but so is the fact that they have the misfortune of being tied to rakshasa and dragons. A rakshasa's immunity to poisons and most dragons' resistances, coupled with the exotic appearance makes having a few vishkanya around both dangerous to one's enemies and pleasing to the eyes.
There are rumors that the vishkanya have ancient cities in southeastern jungles, where the scaled dancers learn to be both courtesan and killer. There are also rumors from those who believe they know such matters that the vishkanya were created as part of an alliance between the serpent folk of the region and the elan rulers of the nearby kingdoms. Vishkanya, for themselves, do not have much concern on either of these rumors. At least, that is the facade that they show the world.
Vishkanya in the west know where their strengths lay, and their culture does not tend to have concerns like morality and "right from wrong" get in the way of one's goals. Sometimes, the serpent has to sleep with the tiger to survive.

Elder Serpents

Possibly even more ancient than the Aasatthi, the Elder Serpents can still be found in ever more remote locations. These sentient snakes claim to be the first of all sentients in Ursu. There is little to contest that statement. Massive serpent skulls have been found buried deep in the earth in locations the world over. At one time, they lived on every landmass, ruling every corner of the world. Even when the race was young, the serpent folk would build large step pyramids for the eldest of serpents to coil around, and rest. It is believed that there may still be anywhere from four to eight of these temple-sized serpents in the world, coiled around some jungle-covered sacred site, rousing only long enough to snap up a passing dragon for a meal. 
Most elder serpents, though, never get to be this size. While large for their species, it is rare for an elder serpent to reach the age needed to gain such size. These snakes never stop growing, but to survive to such an ancient age is a remarkable feat, signifying the power, beyond the physical, that such an entity has.
Elder serpents are far more than just "talking snakes". Most engage in some sort of discipline, be that arcane, divine, psionic, or psychic. One might wonder how a snake can cast an arcane spell, but they are often surprised by how adroit an elder serpent's tail can be, as it gestures out the sommatic components of a spell. The elder serpents state, rather as a matter of fact, that they taught the aasatthi how to cast their first spells. It is very rare to find an elder serpent of any age without some talents in the arts. Most prefer psionic and psychic powers. They do not find being beholden to deities to be too pleasant of an idea, though serpent priests do exist. Also, wizardry and alchemy require too many moving parts for the elder serpents to find enjoyable. It is best to leave those to those willing to carry things about. 
While elder serpents are more involved in their own self-interests, making them possibly dangerous to approach, if done right elder serpents can be excellent sources of wisdom and history. It is rumored that some rulers from the east have been mentored by the great creatures. It is also rumored that one or two were captured and brought to the flying cities of Taoul'Vers. What became of them, if they existed at all, is a mystery.

Sthenoi

The Medusa-Kin hold an odd place among the Scaled Folk. They are not an ancient race that predates humankind. In fact, without humans, the Sthenoi would not exist. The race came about due to the meddling of the wizards of Taoul'Vers. In their interest at the time of crossbreeding almost anything, the wizards tried the breeding of half-medusa humans, to see what would happen. The result was the Sthenoi. The first of these were the children of half-medusae. Then, as if the breeding opened Pandora's Box with the breed, Sthenoi began to appear in Palagea to the children of heroes who had faced a Medusa and barely survived, almost being turned to stone. It was as if the pertrification process left something behind in the blood. The wizards of Taoul'Vers were ecstatic at the development.
The decrease in the number of medusae over the centuries and the understandable related decrease in half-medusae have caused the Sthenoi birth rate to decline accordingly. They still exist, and sometimes are born generations after the introduction of the medusa blood; they do not appear to be going away anytime soon. Right now, though, they are rare.
Not surprisingly, to this day, though rare, most Sthenoi can still be found in and around the Central Sea, more specifically, Palagea. Due to their appearance, regional residence, and similar abilities, Sthenoi are often confused with the Maedu. This confusion, while understandable, does cause some frustration with both groups. Attitudes between the two groups are vastly different, as well. Sthenoi appear to embrace their heritage with a comfort that the cursed Maedu never express.
It is important to note that while most people put the Sthenoi as "Scaled Ones", the majority of the Scaled Races see Sthenoi as either upstarts or not of the group at all.  This opinion has caused some conflict between the Stenoi and the other more ancient races.