Django rest framework: Nested object not passing to validated_data

This is surely a problem in my understanding of how the serializer should work.

After changing a property permissions on my serializer, I found out that my Author nested object is turning out empty on the validated_data.

Here's my code :

class ThreadSerializer(serializers.Serializer):
    class Meta:
            model = Thread
            queryset=Thread.objects.all()
            fields = ('id', 'title', 'description', 'author', 'created_at')

    pk = serializers.IntegerField(read_only=True)
    title = serializers.CharField(required=False, allow_blank=False, max_length=100)
    description = serializers.CharField(style={'base_template': 'textarea.html'}, required=False)
    author = AuthorSerializer()
    created_at = serializers.DateTimeField(required=False)

    def create(self, validated_data):
        """
        Create and return a new `Thread` instance, given the validated data.
        """
        author_data = validated_data.pop('author')
        if author_data:
            author = Author.objects.get_or_create(**author_data)
            validated_data['author'] = author

        return Thread.objects.create(**validated_data)

The payload is also quite simple: { "title": "2", "description": "testing nested objects", "author": { "name": "ron", "email" : "[email protected]" }}

Yet, on the validated_data variable all I see is an empty OrderedDict.

Can someone point me to where I should be fixing this?