No they are not, especially if you are new to barefoot running. For long distance runs you'll want something that gives your feet support, Merrell make other kinds of shoes which are better for long distance running.
Trail shoes are shoes for running in rough terrain. They are bulky and heavy I do not recommend running with them in places were there is not rough terrain.
The best trail running shoes have nylon puncture protection in the sole. Depending on where you are doing your trail running, better shoes will either have crampons or the ability to install them.
A regular pair of running shoes should be sufficient for trail running. But, if you are an avid trail runner, then you can find a pair of specific shoes called the Brooks Adrenaline ASR5.
This website, the 'Running shoe guru' will show you what kind of shoes are best for trail running and have reviews for you. http://www.runningshoesguru.com/best-trail-running-shoes/
Yes there are specific running shoes designed to run on trails. They are called Trail Running Shoes. They are made specifically for trail running just like street running shoes are specifically made for the street.
Merrell has several men's barefoot running shoes that are good for trail running. However, according to Merrell, the Men's Barefoot Run Trail Glove is the best barefoot running shoe for trail running.
The website Zappos.com offers Salomon trail running shoes. They are a discount store. They have a wide selection of running shoes at affordable princing with fast shipping.
If you a running on a trail or trail-type surface, than yes, the asics trail running shoe would be ideal for a marathon. If the marathon is on a hard street surface, then I would research other shoes.
You can buy some trail running shoes at big five sporting goods stores. They have some running shoes to run off track or in the mountains where there are dirt trails.
Nike trail running shoes are durable and last long. They provide good traction and are comfortable. New Balance Minimums Zero running shoes are light, comfortable, and great for running.
There are a number of companies which stock merrell trail running shoes so I would start with the online comparison websites. This way you can find the type of merrell trail running shoes you are looking for and compare the prices at the same time.
You can purchase trail running shoes with many online and in store retailers. It is best to buy in stores, especially for a first pair, so you can try the shoes on.