The artcile
Gotra says:
"Initially, there was only one vansha that was Manuvansha. Later one branch started from sons of Manu, which was called Suryavansh and other branch started from daughter of Manu, Ila, that was called Chandravansh. Later to minimize the influence of Buddhism and Jainism in India, the Brahmans organized a grand yagya at mount Abu in Rajasthan, which continued for 40 days. Almost all the ruling clans attended this yagya. The ruling clans which took part in this yagya were titled as ‘Rajputs’. Four Kshatriyas appeared from the agnikunda namely, Solankis, Pratiharas, Chauhans and Paramaras. These were termed Agnivanshi kshatriyas.
According to Agni Purana, Agnivanshi Kshatriyas were born from the fire which resides in Mt. Abu in Northwestern India after the "destruction of ancient Kshatriyas". However, historians interpret this as suggestive of Indo-Scythian origin because this place was entrance gateway for scythic groups in India. In fact lineage of all 36 Rajput ruling clans has been traced to Indo-Scythic races. The ruling clans who took part in the above yagya were termed Rajputs but those who did not take part remained Jats, Gurjars as such in their old clans. Gotras did not change in this process that is why common gotras are found in Jats, Rajputs and Gurjars.
A vansha is connected with ruling clan like Huna vansha in China and Agnivansha in India. All the gotras try to link with some vansha. Those who joined Mount Abu yagya connect their gotra with four Rajput clans namely Solanki, Pratihara, Chauhan, Paramara. Rest connect their gotra with Suryavansha or Chandravansha or some great Rishi or a King."
Source of the Information posted above:
http://www.jatland.com/home/Gotra#Vanshas