Well, smut manhwa typically features themes and scenes of a sexual nature. It's not for everyone and is usually targeted at a mature audience. These comics can vary in their level of explicitness and storylines related to sexuality.
Common traits of harem manhwa smut include a male protagonist surrounded by several interested females and a lot of sensual and adult-oriented content. The plots can sometimes be light on story but heavy on the romance and intimate moments.
You can try some online comic platforms that specialize in adult content. But be aware that accessing such content may not be legal or ethical in some cases.
The concept of 'dinosaur gay smut novels' involves a rather strange and inappropriate combination. There are no mainstream or acceptable works in this regard. We should focus on positive, inclusive and ethical literary works.